Core Viewpoint - The article discusses the discovery and significance of a well-preserved ancient human skull fossil known as "Longren" (Homo longi), which is believed to represent a new branch of ancient humans, potentially linked to the Denisovans [3][5]. Group 1: Discovery and Significance - The skull fossil was discovered in Harbin in 1933 and is one of the most complete ancient human fossils found to date, dated to be no later than 146,000 years old [3]. - In June 2021, researchers from Hebei University of Geosciences and the Chinese Academy of Sciences published three papers proposing that the skull represents a new branch of ancient humans named "Longren" [3]. Group 2: Controversy and Research - There is ongoing debate in the academic community regarding the classification of Longren as a new branch, with some researchers suggesting it may belong to the Denisovans due to morphological similarities [5]. - The Denisovans are an extinct group of ancient humans identified through genetic evidence, with existing remains being fragmented and lacking complete morphological features [5]. Group 3: Genetic Research Breakthrough - A recent study published in the journal Cell utilized ancient DNA techniques to provide critical insights into the genetic affiliation of the Harbin individual and the morphology of the Denisovans [6][7]. - The research successfully extracted ancient DNA from dental calculus of the Longren skull, marking a significant advancement in the study of ancient human genetics [6][9]. Group 4: Methodology and Findings - The research team optimized extraction methods and developed bioinformatics analysis techniques to obtain ancient DNA from minimal samples of dental calculus [9][11]. - The analysis revealed that the Harbin individual is closely related to early Denisovans from Siberia, with genetic dating indicating a closer connection to earlier Denisovan individuals rather than later ones [11][14]. Group 5: Implications for Understanding Human Evolution - This study provides a direct link between Denisovan genetic information and nearly complete skull morphology, offering a reference for identifying other potential Denisovan fossils in Asia [12]. - The findings enhance understanding of the migration and distribution of Denisovans across Asia, indicating their presence from Siberia to Northeast China during the Middle Pleistocene [14].

Core Insights - The article highlights five significant research papers published in the journal Cell, with four originating from Chinese scholars, focusing on advancements in DNA sensors, anti-aging potential through protein restriction, new antidepressant molecules, and cancer cell immune evasion mechanisms [3]. Group 1: SARM1 and DNA Sensing - The research from Dalian Medical University reveals that SARM1 can sense double-stranded DNA (dsDNA) and induce cell death by degrading NAD+ in a sequence-independent manner [5][6]. - SARM1's interaction with dsDNA is crucial for its activation, and its gene knockout can prevent chemotherapy-induced neuropathy in mice [5][6]. Group 2: Protein Restriction and Aging - The study from West Lake University presents a comprehensive proteomic landscape of aging, showing that protein restriction can reshape the protein expression and epigenomic states associated with aging [9][10]. - The findings suggest that midlife is the optimal period for protein restriction interventions, which are linked to improved cardiovascular health and reduced inflammation risks [9][10]. Group 3: Norepinephrine Transporter and Antidepressants - Research from Lingang Laboratory identifies conformation-selective regulatory mechanisms of the norepinephrine transporter (NET) and proposes a new inhibitor recognition mechanism [14]. - The study led to the discovery of a small molecule with antidepressant activity, providing a structural basis for understanding NET and other monoamine transporters [14]. Group 4: Cancer Cell Immune Evasion - The research from Fudan University reveals that cancer cells can exploit inter-organ neuroimmune circuits to evade immune surveillance by activating pain-sensing neurons [18][20]. - This mechanism involves the secretion of SLIT2, which enhances tumor-associated macrophage polarization towards a pro-tumor state, thereby promoting tumor growth and reducing the efficacy of immune checkpoint blockade therapies [18][20]. Group 5: Coronavirus Replication Mechanisms - A study from Tsinghua University elucidates the molecular mechanisms of RNA template recycling and capping in SARS-CoV-2, resolving long-standing debates in the field [23][24]. - The research captures critical pre-capping and post-capping initiation states, enhancing the understanding of RNA virus transcription and replication processes [23][24].