Analysis of total and surface protein levels of CD79A, CD79B, and IgM/IgG in isogenic DLBCL cell lines with endogenous KLHL6 (parental), or overexpression of KLHL6WT or recurrent mutants revealed differential impacts by the BTB and Kelch mutations on the BCR phenotype. The gene discussed is CD40LG; the disease is diffuse large B-cell lymphoma.