ATF6 and pachyonychia congenita: The result of the CCK8 assay showed that ATF6 overexpression and EMC6 or APAF1 knockdown enhances the growth of PC cells (Figures 5B,D,G), whereas ATF6 knockdown and EMC6 or APAF1 overexpression decreases the proliferation of PC cells compared with the control (Figures 5A,E,H).