As shown in Figure 6A, in cells infected with the virulent H37Rv strain at an MOI of 0.1, slightly higher levels of TNF-α were secreted by the DBA/2 BMDMs following infection with H37Rv compared with the BALB/c and C57BL/6 BMDMs, whereas when cells were infected with this strain at an MOI of 1, slightly lower levels of TNF-α were secreted by the DBA/2 BMDMs than the BALB/c and C57BL/6 BMDMs. This evidence concerns the gene TNF and infection.