Stanniocalcin 1 (STC1) is a secreted protein with pleiotropic functions in calcium homeostasis, cellular senescence, and disease pathogenesis. Originally characterized for stimulating renal phosphate reabsorption to prevent hypercalcemia, STC1 has emerged as a critical regulator in multiple pathophysiological contexts 1. In asthma, STC1 functions as an epithelium-derived relaxing factor that suppresses airway smooth muscle contraction by blocking store-operated calcium entry through STIM1 inhibition; asthmatic patients show reduced serum STC1 levels that correlate inversely with airway hyperresponsiveness 1. STC1 serves as a senescence-associated secretory phenotype (SASP) biomarker that correlates with chr8 age in human plasma 2. In cancer, STC1 functions as an immune checkpoint molecule operating as a "don't eat me" signal; in colorectal cancer, STC1 suppresses the "eat-me" calreticulin signal on cancer cell membranes, promoting immune evasion and reducing response to immunotherapy 3. In ovarian cancer, STC1 promotes metastasis, lipid metabolism, and cisplatin chemoresistance through FOXC2/ITGB6/PI3K signaling 4. In inflammatory bowel disease, STC1 expression is elevated in Crohn's disease and promotes oxidative stress-induced parthanatos through PARP1-JNK pathway activation, aggravating colitis 5. In pancreatic cancer, lactylation-modified NSUN2 stabilizes STC1 mRNA to promote perineural invasion 6. STC1 variants regulate adult kidney function through tubule epithelial chr8 accessibility 7.