Whilst the level of H3K4me3 modification of telomeric histone was unaffected by retinoblastoma status (p = 0.5016), the representation of both H3K9me3 and H3K9ac in the telomeric chromatin was significantly increased in haploinsufficient (Rb1+/Δ19) cells (Fig. 1B). Here, RB1 is linked to retinoblastoma.