APOL6 and urinary bladder cancer: APOL consists of APOL1, APOL2, APOL3, APOL4, APOL5, and APOL6, whose structures and functions are similar to those of the proteins of the Bcl‐2 family.79 APOL1 mRNA and protein expression was significantly elevated in the tissue of papillary thyroid carcinomas.80 Expression levels of APOL2 could predict the survival time of patients with bladder cancer.81 The APOL3 region on chromosome 22q12 was found to be a risk locus in hereditary prostate cancer.82 APOL6 was identified as homologous to a Bcl‐2 protein and could induce apoptosis mediated by mitochondria in cancer cells.83