Among TFs, we found that, similar to Arabidopsis, the transcription level of FER and subgroup Ib bHLH TFs were induced by Fe deficiency, while genes encoding subgroup IVc bHLH TFs, that is, SlbHLH104, SlbHLH115, and SlILR3, were mostly not responding to Fe deficiency at the transcriptional level, with exception of SlILR3. Here, FER is linked to hyperinsulinemic hypoglycemia, familial, 4.