Heat Shock Protein BAP1 (heat shock 27-kDa-associated protein 1, or HSPBAP1) inhibits the function of heat shock protein 27, which has a neuroprotective effect during experimentally induced epileptic neuropathology. The HSPBAP1 protein, also known as PASS1, contains a jmjC motif, suggesting it is a member of the jumonji family of transcription factors. There is evidence of domain swapping within the jumonji family genes, and the HSPBAP1 gene has been shown to fuse with a novel gene called DIRC3 in hereditary renal cell cancer.