Surprisingly, when we immunoprecipitated the HP1γ-WT, -K5R and -K5Q proteins, we did not observe distinct changes in their interactions with MDC1, HDAC1 and H3K9me3 (Supplementary Fig. 6e), despite that overexpression of HP1γ-K5R in MM cells indeed elicited stronger chemoresistance and proliferation (Supplementary Fig. 6f, g). This evidence concerns the gene MDC1 and Miyoshi myopathy.