This is remarkable to note since neoplastic HMC‐1 mast cell lines carry constitutively active KIT variants (Sundström et al., 2003), similar to clonal mast cell populations in mastocytosis (Longley et al., 1999; Nagata et al., 1995; Worobec et al., 1998) and epithelial cells in GIST (Hirota et al., 1998). The gene discussed is KIT; the disease is gastrointestinal stromal tumor.