Northern blot analysis of MAL expression. Fifteen micrograms of total RNAs extracted from PMBLs, peripheral DLBLs, and human cell lines was loaded per lane. Hybond N+ membranes were hybridized with a PCR-derived MAL cDNA fragment (upper panel), stripped, and rehybridized with a GAPDH probe (lower panel) to check the RNA amounts loaded and transferred to the membrane. (A) RNAs from Jurkat T-cell line, 2 PMBLs (no. 11 and 12), and 4 peripheral DLBLs (no. 15, 17, 18, and 16). (B) RNAs from human cell lines. Hela is nonhematopoietic. HEL and K562 are erythroleukemic cell lines. Jurkat is a T-cell line. Raji and Ramos are derived from Burkitt’s lymphoma. RL bears the t(14;18) translocation associated with follicular lymphoma. 697 is a pre-B–cell line and RS 4:11 a pro-B–cell line.