As IRP1 and IRP2 regulate IRE-containing genes at the post-transcriptional level35, we validated the observed changes in mRNA expression in PBMCs from 21 day 0–14 COVID-19 samples using mass spectrometry (groups A + B, n = 7; group C, n = 5; groups D + E, n = 9)36. The gene discussed is IREB2; the disease is COVID-19.