IFIH1 and infection: While single-cycle HIV-1 (LaiΔenvGFP/G) infection of THP-1/PMA macrophages with reduced expression of RIG-I, MDA5, or UNC93B1 was unaffected compared with control shRNA-expressing cells (Figure 2B), we found that only MDA5, but not RIG-1 or UNC93B1, knockdown resulted in significant downregulation of HIV-1 icRNA-induced IP-10 production (Figure 2C).