STAT3 regulates CBX4 via the regulation of ∆Np63α. (A) Control, p63-sgRNA and p63-sgRNA + ∆Np63α-expressing cells were harvested for protein for western blot. (B) Control, STAT3C, p63-sgRNA and STAT3C + p63-sgRNA-expressing cells were harvested for protein for western blotting of the indicated proteins. (C) Control, STAT3C, p63-sgRNA and STAT3C + p63-sgRNA-expressing cells were seeded in spheroid growth conditions and the spheroid number was monitored for 9 days. (D) Control, STAT3C, p63-sgRNA and STAT3C + p63-sgRNA-expressing cells were seeded on Matrigel-coated membranes for an invasion assay, and the number of invading cells was counted after 24 h. (E) HSC-5 cells infected with lentivirus expressing ∆Np63α or empty vector were treated with STATTIC or DMSO and lysates were collected for immunoblot. (F) Control- and p63-sgRNA ± CBX4-expressing cells were harvested for protein and seeded in spheroid conditions (G), or invasion assays (H) and spheroid number and rate of invasion were monitored, respectively, *, **, P < 0.05 (the double asterisk indicates significance compared with the single asterisk group).