To investigate the roles of BCR signaling modulation in antitumor immunity, the study in this issue of the JCI by Bing Yang, Zhen Zhang, et al. (14) followed up on their recent report on an Asia-specific variant of human immunoglobulin G1 (IgG1) containing a Gly396 to Arg396 substitution (hIgG1-G396R) in colorectal cancer (CRC). This evidence concerns the gene BCR and colorectal carcinoma.