ATF3 and gastric cancer: To investigate the biological implications of ATF3 in GC, based on the mRNA and protein expression levels of ATF3 among 9 GC cell lines (Supplementary Fig. 1a–e), we used lentiviral transduction to knock down ATF3 expression in AGS and HGC-27 cells and overexpress ATF3 in MGC-803 and MKN-45 cells.