CD74 and neoplasm: CD74, in particular, acts as a marker of these B cells and functions as a crucial MHC class II molecular chaperone, facilitating antigen presentation and enhancing T‐cell accumulation and function within the tumor microenvironment.[19, 55, 56] These distinctive features of early stage CD74+ B cells suggest that their interactions with naive T cells may be pivotal in shaping the immune response in PSCC, thereby promoting stronger immune activation and contributing to antitumor immunity.