ATF3 and cancer: To further illustrate the role of ATF3 in CRC, we treated cells with sangivamycin (Supplementary Fig. S4C), which was reported to upregulate the expression level of ATF3 [55] and inhibit the proliferation of a variety of human cancer cells, including colon carcinoma cells [56], a significant increase in ATF3 expression was observed in sangivamycin-treated samples under both monolayer (Fig. 4I) and MCTS conditions but not in ATF3KO cells (Fig. 4J).