Relative expression of restriction factors in SM and RM macrophages after SIV infection. The expression of restriction factors and classical ISGs MX1, MX2, and OAS2 were measured relative to the housekeeping gene GAPDH at day 21 after in vitro infection with SIVM949 in MDMs of SMs and RMs. In this part of the study, we examined a total of five RM-derived MDMs and six SM-derived MDMs that were exposed to different doses of virus (i.e., ranging between 400 and 3,200 pg p27 equivalents) for a total of 7 and 10 data points for RM and SM, respectively.