C1QBP and neoplasm: In non-small cell lung cancer, MHC-II expressing antigen-presenting cancer-associated fibroblasts evade immune cell-mediated apoptosis by antigen-stimulated production of C1q, which interacts with the complement C1q binding protein (C1QBP) on CD4+ T cells, impairing their antitumor effects and contributing to tumor progression (29).