JCHAIN and neoplasm: We found IGHA1, IGHA2, and JCHAIN were significantly decreased in neoadjuvant MPR tumor lesions than in non-MPR tumor lesions, while IGHG1 and IGHG3 were significantly upregulated in MPR tumor lesions (Fig. 2C), indicating the B cells class switched to two dominant antibody isotype IgG1 and IgG3 during neoadjuvant chemoimmunotherapy.