In 2011, Varela et al. reported that the PBRM1 gene is mutated in approximately 40% of clear cell renal cell carcinoma cases. Since then, the number of studies relating PBRM1 mutations to cancers has substantially increased. BAF180 has now been linked to more than 30 types of cancers, including ccRCC, cholangiocarcinomas, esophageal squamous cell carcinoma, bladder cancer, and breast cancer. The mutations associated with BAF180 are most often truncations, which result in a loss of protein expression. This loss has been shown to adversely affect the expression of genes, likely because BAF180 is the chromatin recognition subunit of PBAF. In addition, BAF180 functions in numerous DNA repair mechanisms. Its roles in mediating DNA repair are likely the mechanism by which BAF180 acts a tumor suppressor protein. As research on this protein gains more interest, scientists will begin to piece together the complicated puzzle of the BAF180 protein and why its loss often results in cancer.