STK16 is a ubiquitously expressed, myristoylated serine/threonine protein kinase belonging to the NAK kinase family that functions primarily as a membrane-associated protein localized to the Golgi apparatus 1. As a kinase, STK16 phosphorylates multiple substrates including STAT3 (at ser-727), WDR1, and actin-binding proteins, and exhibits autophosphorylation activity 234. Mechanistically, STK16 regulates actin dynamics to control Golgi organization and cell cycle progression, with STK16 knockdown disrupting actin polymers and causing Golgi fragmentation and cell cycle arrest 4. STK16 participates in multiple cellular processes including TGF-β signaling, trans-Golgi network protein secretion and sorting, and hepatocyte polarized secretion 13. Clinically, STK16 has emerged as a therapeutic target in triple-negative breast cancer (TNBC), where elevated STK16 expression confers resistance to JAK2 inhibitors by maintaining STAT3 phosphorylation; dual JAK2/STK16 inhibition improves therapeutic efficacy 2. Additionally, STK16 inhibition selectively suppresses non-adrenergic smooth muscle contractions in prostate and bladder tissues, suggesting potential therapeutic utility for lower urinary tract symptoms 5. Selective STK16 inhibitor STK16-IN-1 has been developed and shows promise in preclinical studies 6.