On the one hand, the BTK inhibitor ibrutinib has significant value for the treatment of human DLBCL patients, particularly with ABC-DLBCL subtype [7], and has been shown to exert dose-dependent proliferation inhibition and IgE-dependent histamine release suppression in a pre-clinical model of canine mast cell tumor [21]. The gene discussed is BTK; the disease is mast cell neoplasm.