A study by Park and colleagues [56] demonstrated that butyrate significantly enhances radiosensitivity in patient-derived organoids (PDOs) of colorectal cancer (CRC) by enhancing the transcriptional function of Forkhead box class O 3 A (FOXO3A) and inducing cell cycle arrest through the regulation of p21, p57, and GADD45. The gene discussed is GADD45A; the disease is colorectal carcinoma.