LY6G6D (lymphocyte antigen 6 family member G6D) is a glycosylphosphatidylinositol-anchored membrane protein that functions as a tumor-associated antigen in colorectal cancer (CRC) 1. This protein is selectively expressed on CRC cells, particularly in microsatellite-stable (MSS) subtypes, with minimal expression in normal tissues 23. LY6G6D expression is regulated through JAK/STAT5 signaling and DNA methylation mechanisms, with elevated expression associated with APC and p53 mutations 45. Mechanistically, LY6G6D contributes to immune evasion by promoting an immunosuppressive tumor microenvironment characterized by regulatory T-cell enrichment and reduced immune infiltration 46. Clinically, LY6G6D overexpression correlates with poor prognosis and metastatic relapse risk 47. Therapeutically, LY6G6D serves as an excellent target for T-cell engagers and bispecific antibodies that redirect cytotoxic T-cells to lyse LY6G6D-expressing tumors, demonstrating potent antitumor activity in preclinical models and potential efficacy in MSS CRC patients resistant to checkpoint inhibitors 23. Combined targeting of LY6G6D with immune checkpoint inhibition or MAPK pathway inhibitors shows enhanced therapeutic potential 4.