Furthermore, it has been reported in a patient with MMR-deficient colon adenocarcinoma that NK cell activity has been affected by the increased frequency of M2 macrophages which interfere with NK degranulation, thereby hampering the response and shedding light on the immunosuppressive tumour microenvironment in MMR-deficient patients [41]. The gene discussed is MRC1; the disease is colon adenocarcinoma.