PIN1 and neoplasm: Pin1 also catalyzes the isomerization of Pro205 of Brd4 and induces its conformational change through a cis-trans isomerization, which leads to enhanced CDK9 binding to Brd4 and enhanced recruitment of CDK9 to a subset of promoters of Brd4-mediated tumor-promoting genes, including c-MET and MMP9 (Hu et al., 2017).