The increase in lesional MRGPRX2+ cells as compared to non-lesional skin was slightly higher in MF (2.21 times higher, mean: 15.12 vs. 6.84 cells/mm2) as compared to previously reported in chronic prurigo (1.50 times higher, mean: 3.98 vs. 2.66 cells/mm2) (12) but lower than in indolent systemic mastocytosis (4.29 times higher, median: 22.3 vs. 5.2 cells/mm2) (9). The gene discussed is MRGPRX2; the disease is mycosis fungoides.