SLC11A2 and hyperinsulinemic hypoglycemia, familial, 4: The expression level of bHLH121-like, PYE1, BTS1, YSL1, YSL2, NRAMP2, FRO8 and CCH was not significantly affected by Fe deficiency treatment (fold change < 2), indicating these genes are responsive to excess Cu, rather than Fe deficiency.