SASH1 (SAM and SH3 domain containing 1) is a multifunctional scaffold protein that plays crucial roles in cellular signaling, melanocyte biology, and tumor suppression. SASH1 functions as a positive regulator of NF-κB signaling by assembling molecular complexes containing TRAF6, MAP3K7, CHUK, and IKBKB, facilitating NF-κB activation downstream of TLR4 1. The protein regulates cellular mobility, including LPS-induced endothelial cell migration and melanocyte migration in skin pigmentation control 12. SASH1 promotes melanocyte stem cell maintenance through interaction with tankyrase 2 (TNKS2), with mutations like S519N causing defects in this function and leading to accelerated hair graying and skin dyspigmentation 3. Disease-wise, SASH1 mutations are associated with dyschromatosis universalis hereditaria, causing hyper- and hypopigmented macules 4. SASH1 acts as a tumor suppressor, with reduced expression observed in various cancers including head and neck squamous cell carcinoma and cutaneous squamous cell carcinoma, where it suppresses proliferation and invasion through Akt pathway inhibition 56. Additionally, SASH1 is involved in pregnancy-related disorders, with increased expression in preeclampsia affecting trophoblast function 7.