Granzyme B is involved in the pathophysiology of viral and bacterial infections, solid organ rejection, autoimmune diseases, and antitumor immunity.[25], [26], [27], [28], [29], [30] In the granzyme B gene, a triple-mutated allele (Q48R, P88A, and Y245H) in strong linkage disequilibrium is found in European, African, and Asian populations, including the Japanese population, at an allelic frequency of 25–30%.[31], [32] The biological and functional relevance of the RAH mutant granzyme B, however, still remains controversial. This evidence concerns the gene GZMB and autoimmune disease.