The detection of CD30 in neoplastic MCs in indolent forms of mastocytosis have been rarely described.[11] Although there is no reliable biomarker that correlates with the prognosis, a possible relationship between CD30 expression and a worse outcome has been described almost exclusively in aggressive forms of SM.[7] To investigate the prognosis value of CD30 in mastocytosis, we tested CD30 immunostaining in a retrospective series of CM and SM patients. Here, TNFRSF8 is linked to systemic mastocytosis.