SMC1A and cancer: HUWE1 revealed exclusively monoallelic enrichment for all three marks, consistent with its silence on the Xi in all lines (Supplemental Fig. S7C), whereas escapees SMC1A and DDX3X and several “cancer-specific” escapees displayed biallelic H3K4me3 and RNA Pol II, with monoallelic H3K27me3 (Supplemental Fig. S7C,D).