In uveal melanoma, which has many similarities with dMMR CRC (preferential haematogenous spread to the liver and similar B2M mutation pattern), loss of HLA‐class I/B2M expression is also associated with significantly improved survival.24, 25 The role of NK activity and HLA class I loss in the prevention of distant metastases has been extensively investigated in uveal melanoma and fibrosarcoma, in both in in‐vitro studies and mouse models.26, 27, 28, 29. Here, B2M is linked to fibrosarcoma.