SQSTM1 and colorectal carcinoma: To confirm the physical interaction between p62 and GATA4 and to determine whether the interaction might be altered under extracellular acidosis, we immunoprecipitated p62 with the anti-p62 antibody and then measured the amount of GATA4 that binds p62 in CRC cells grown under pH 7.4 and pH 6.5, respectively.