Chromobox (CBX) members, such as CBX1-8 proteins, are essential components of polycomb group (PcG) protein complexes.4 Several members of the PcG complex have been described as epigenetic drivers in human cancers, including CRC.5 CBX2, an oncogene, has been associated with several tumours, including tumours originating from liver, stomach and prostate.6-8 Although recent research revealed that CBX2 expression and prognostic significance may be associated with CRC,9 more convincing evidence is still needed. Here, CBX1 is linked to cancer.