A genetically modified NOD.Cg-Prkdc scid Il2rg tm1Wjl /SzJ mouse is provided by the present invention wherein the genome of the mouse includes a mutated Rhbdf2 gene such that the mouse expresses a mutant iRhom2 protein, wherein the mutant iRhom2 protein differs from wild-type iRhom2 protein due to one or more mutations selected from p.I156T, p.D158N and p.P159L, and wherein the mouse is characterized by hairless phenotype and increased growth of an exogenous tumor compared to a mouse of the same genetic background which express wild-type iRhom2 protein.