Combined treatment with mesalamine and PTX resulted in a 2.8‐fold increase in Nrf2 (F = 128.2, p < 0.0001) and a 3.28‐fold increase in HO‐1 (F = 141.7, p < 0.0001), significantly higher than those observed in the colitis group. The gene discussed is HMOX1; the disease is colitis.