TSSK6 is a testis-specific serine/threonine kinase with critical roles in male reproduction and emerging oncogenic functions. In normal physiology, TSSK6 is essential for spermatogenesis, localizing to spermatid and regulating sperm development through MYC-related pathway suppression 1. TSSK6 knockout mice exhibit infertility with reduced sperm count, motility, and increased morphological abnormalities 2, while zebrafish studies confirm its evolutionary conservation and role in testis development and sperm quality 3. At the molecular level, TSSK6 likely functions as a serine/threonine kinase mediating phosphorylation events critical for spermatogenesis and male fertility. Clinically, TSSK6 demonstrates an oncogenic dual nature when aberrantly expressed. As a cancer testis antigen, TSSK6 is frequently upregulated in colorectal cancer, where elevated expression correlates with reduced relapse-free survival 45. Mechanistically, TSSK6 kinase activity promotes anchorage-independent growth, invasion, and focal adhesion formation in cancer cells 4. In somatic contexts, TSSK6 can confer malignant properties to semi-transformed epithelial cells independently 5. Pharmacoeconomically, TSSK6 emerged as a druggable target across multiple disease contexts: colorectal cancer precision therapy 6, myopia pathogenesis 7, and seborrheic keratosis susceptibility 8. Its restricted normal expression suggests a potentially broad therapeutic window with minimal off-target effects in non-reproductive tissues.