PBRM1 and breast cancer: Extensive sequencing projects by TCGA have identified PBRM1 as the second most frequently altered gene in ccRCC (49% of explored cases, 163 point mutations, eight deep deletions, and one fusion in a total of 354 cases) [20,31] Even though ccRCC is the tumor type with the highest mutational rate in PBRM1 in the TCGA Pan-Can Project [32], somatic PBRM1 mutations were first described in breast cancer [29] and are also observed in other cancer types such as cholangiocarcinoma (22%) and uterine (10%).