Ubiquitin-conjugating enzyme E2 D1 (UBE2D1), a member of human E2 ubiquitin-conjugating enzymes, is closely related to SFT, which is short for stimulator of iron (Fe) transport. In other words, UbcH5A is significantly up-regulated in the liver of iron-overloaded patients with hereditary hemochromatosis, as previously published for SFT. Moreover, a complex of UBE2D1 is critical in maintaining KRAS protein stability and propose that targeting such complex may be a unique strategy to degrade mutant KRAS to kill cancer cells.