FDX1 and neoplasm: We note that Xie M. et al. verified that FDX1, a cuproptosis master regulator, was downregulated in clear cell renal cell carcinoma to promote malignant biological properties; from interaction assays, FDX1 was identified as a target gene of miR-21-5p; miR-21-5p negatively regulated FDX1 expression to suppress Cu cell death effects for better tumor progress (Xie et al., 2022).