SLC6A6 and neoplasm: Notably, tumor cell–restricted taurine transporter SLC6A6 expression correlates with spatial exclusion of CD8+ T cells, implicating metabolic competition as a driver of immune privilege (11, 12).Multi-omics approaches integrating single-cell and proteomic data have further identified semi-squamous differentiation as a marker of MIBC chemoresistance, with cathepsin CTSH emerging as a target for inducing terminal differentiation in resistant clones.