UNC4976 TFA is a peptidomimetic CBX7 chromodomain positive allosteric modulator (PAM). It functions by disrupting the specific recruitment of CBX7 to H3K27me3-marked genes while promoting its non-specific binding to DNA and RNA. This compound is a valuable chemical probe for studying Polycomb repressive complex 1 (PRC1) function in epigenetic regulation, applicable in both in vitro binding assays and cellular models.