Jundt et al. have also described the tumor-promoting role of Notch in myeloma, showing that Notch1, Notch2 and Jagged1 are strongly expressed in myeloma cell lines, but are often missing in normal plasma cells, with Notch activation through both homotypic and heterotypic interactions causing increased tumor cell growth [92]. The gene discussed is JAG1; the disease is plasma cell myeloma.