In this study, we screened three immune-related CM prognostic mRNAs: SUCO, BTN3A1 and TBC1D2. The hazard ratios (HRs) of SUCO and BTN3A1 were < 1, indicating that their increased expression led to a reduced risk of death in CM patients and that they are tumour suppressor genes in CM. Here, BTN3A1 is linked to cutaneous mastocytosis.