PBRM1 (Polybromo 1): PBRM1 is a subunit of the SWI/SNF chromatin remodelling complex that helps regulate gene expression by modifying chromatin structure. It acts as a tumour suppressor, and mutations in PBRM1 have been linked to several cancers, especially clear cell renal cell carcinoma. Its role in chromatin remodelling is essential for preserving genomic integrity and supporting normal cell function.