Once that a high expression of JAK1 has been identified in individuals with JAK1 c.991-27CC genotype in this study, we believe that JAK1 c.991-27C>T SNV may have contributed to the STAT3 SNV in maintaining JAK/STAT pathway activation, presenting a greater chance of CM development and progression as a consequence. This evidence concerns the gene JAK1 and cutaneous mastocytosis.