Mechanistically, ALDH1A1 decreased the intracellular pH in breast cancer cells to promote phosphorylation of TAK1, activate NF-κB signaling, and increase the secretion of GM-CSF, which led to myeloid-derived suppressor cell expansion and immunosuppression (Liu et al., 2021) (Figure 1C). This evidence concerns the gene ALDH1A1 and breast cancer.