CTSV (cathepsin V) is a cysteine protease with diverse roles in cancer progression, cardiovascular protection, and cellular senescence. In cancer, CTSV functions as an oncogene promoting metastasis through regulation of cell migration and invasion. High CTSV expression is associated with poor prognosis in multiple cancer types including renal cell carcinoma 1, colorectal cancer 2, liver cancer 3, gastric cancer 4, and breast ductal carcinoma in situ 5. The protein promotes cancer cell invasiveness through multiple signaling pathways, including EGFR-MEK-ERK 1 and PKC-ERK-Sp1 axes 2. Conversely, CTSV exhibits protective functions in cardiovascular tissue, where exogenous CTSV protein prevents angiotensin II-induced cardiac hypertrophy by inhibiting PI3K/Akt/mTOR and MAPK pathways 6. CTSV also regulates endothelial cell senescence by modulating the ALDH1A2-AKT/ERK1/2-p21 pathway 7. In the nervous system, CTSV is involved in neuropeptide production and shows widespread expression throughout human brain regions, particularly in white matter 8. The protein's dual role as both a tumor promoter and cardiovascular protector highlights its context-dependent functional significance.