Mimicking the provision of IFN-I by other cells, addition of exogenous IFN-β or IFN-α 4 h post infection led in a dose dependent manner to greater death at 2 days post infection of Mtb-infected MDM-1 (Fig. 6A,B; Appendix Figs. S3A,B and S4A,B). This evidence concerns the gene IFNB1 and infection.