PTEN and hepatocellular carcinoma: To do this, we performed chromatin immunoprecipitation (ChIP) coupled with qPCR for H3K27Me3, the mark of PRC2-mediated transcriptional repression, in the HCC-1187 TNBC cell line, which we selected because it is PTEN wild-type, exhibited marked co-downregulation of PTEN and ATAD1 (Fig. 1a), and showed the greatest amount of reporter activation when portions of the PTEN promoter were deleted (Fig. 2b).