Since the CD1dhiCD5+ B cell population has been shown to mediate immune-suppression via IL-10 secretion [37, 38] and IL-35 [77] in mouse autoimmune and tumor models, Pylayeva-Gupta et al. investigators hypothesized that CD1dhiCD5+ B cells would also regulate immune-suppression and promote tumor growth in the mouse pancreatic ductal adenocarcinoma (PDAC) model. This evidence concerns the gene IL10 and neoplasm.