Itwas intriguing to have found that Tβ4, PRP-3 desR106, cystatin D-R26 des1-5, and P-B des1-5, which correlatedwith tryptase, allowed us to distinguish the two subgroups of SM patients.These results were suggestive of considering them as promising biomarkersfor a differential diagnosis of the disease. The gene discussed is CST5; the disease is systemic mastocytosis.