Further detailed analysis within the B-cell/plasma cell population showed a diminished presence of B-cells marked by Cd19 and Pax5 expression in TC-RK mice, in stark contrast to the prevalent CD138/Sdc1+ plasma cells, also characterized by the expression of genes associated with myeloma, such as Slamf7, Tnfrsf17 (BCMA)—a target for CAR-T-cell therapy—along with Cd74, Mzb1, Enpp1, and the autophagy gene Sqstm1 (p62) (Fig. 5d). Here, CD19 is linked to plasma cell myeloma.