Novel molecular biomarkers and approaches are emerging to enhance diagnostics and prognostics across oncology and neurology. Studies identify plasma microRNAs linked to peritoneal carcinomatosis in gastric cancer and reveal a U-shaped serum LDH relationship with mortality in cancer patients. In the neurological domain, proteomic analysis draws parallels between Down syndrome neuropathology and Alzheimer’s disease. Furthermore, insights into glioma radiosensitivity molecular markers and synaptic dysfunction driven by glial reactivity in aging and Alzheimer’s provide new therapeutic angles. These findings collectively promote early detection and tailored treatment strategies.