IGHV1-2 and infection: The XJ strain infection group expressed IGHV8-12-IGHJ1, IGHV12-3-IGHJ4 and IGHV1S134-IGHJ4 genes, but did not express IGHV1-12-IGHJ1, IGHV1-22-IGHJ1, IGHV1-50-IGHJ2 and IGHV1-30-IGHJ3 genes in comparison with Bartha-K61 strain infection.