TSC22D2 is a growth-suppressive adaptor protein that functions through multiple regulatory pathways. Primarily, TSC22D2 reduces nuclear localization of pyruvate kinase M2 (PKM2) isoform, thereby repressing cyclin D1 transcription and inhibiting cell growth 1. TSC22D2 is significantly downregulated in colorectal cancer, with overexpression demonstrating growth-inhibitory effects 1. Beyond oncogenic control, TSC22D2 participates in osmotic stress responses as part of a functional buffering system with WNK kinases and NRBP1 proteins, regulating rapid cell volume homeostasis through biomolecular condensate formation 2. In kidney distal convoluted tubules, TSC22D2 serves as a positive modulator of WNK signaling, influencing sodium reabsorption and epithelial ion transport 3. During inflammatory responses, anti-inflammatory miRNAs suppress TSC22D2 expression, which promotes regulatory T cell differentiation via STAT3 signaling and inhibits pro-inflammatory M1-macrophage polarization 4. A novel TSC22D2 mutation (c.-91T-C) cosegregated with multi-cancer phenotypes in a familial pedigree 5. TSC22D2 represents a promising biomarker for pancreatic adenocarcinoma prognosis, with elevated expression correlating with worse outcomes 6. Functionally, TSC22D2 exhibits dual roles as both a tumor suppressor and osmotic regulator through protein-protein interactions.