CD8A and Miyoshi myopathy: Compared to control mice, tumor load in treated mice was approximately 100-fold lower, demonstrating strong in vivo anti-tumor responses (Fig. 7B). To conclude, our data show that identified Jchain A1, A3, A11, and A24 TCRs demonstrate potent anti-MM responses when transferred to CD8 T cells, both in vitro against patient-derived primary MM samples and in vivo against JCHAINpos MM cell line U266.