Ji et al demonstrated that CUDC‐101, a multitargeted inhibitor of HDAC, EGFR, and HER2, applied with GEM can not only induce apoptosis via PI3K/mTOR signaling, but also reduce GEM resistance of PC by inhibiting cell proliferation and EMT in PC via the ERK/Snail signaling pathway.28 This evidence concerns the gene ERBB2 and pachyonychia congenita.