Prior to developing the multitarget hybrid drug, to confirm the potential synergistic response of HDAC and PI3K inhibition, individual effects of HDACI vorinostat (SAHA) and PI3K inhibitor pictilisib (GDC-0941) on growth inhibition of human PC-3 prostate cancer cells were determined [135]. This evidence concerns the gene HDAC9 and prostate carcinoma.