IFNG and COVID-19: To elucidate how ‘linked hypo-DMRs’ facilitate IFN-γ response gene expression in COVID-19 patients with CHIP, we examined the regulatory potential of hypo-DMRs based on four representative histone modification marks of primary human classical monocytes: histone H3 4th lysine monomethylation (H3K4me1) and trimethylation (H3K4me3) and 27th lysine acetylation (H3K27ac) and trimethylation (H3K27me3)45,46.