CDR1 and hydrops fetalis: Our CUT&RUN analysis found HF-Mrr1L1Q1*-bound DNA to be significantly enriched in the upstream intergenic regions of MDR1, CDR1, and FLU1 ORFs (Fig. 7C through E) with a peak profile identical to HF-Mrr1ancestral and HF-Mrr1Y813C.