IL1B and infection: However, when we treated THP-1 monocytes (Figure 2A), THP-1 derived macrophages (Figure 2B), human primary monocytes (Figure 2C) and macrophages (either unprimed or LPS primed) (Figure 2D–E) with purified HCV virions at a multiplicity of infection (MOI) from 0.001 to 2 as indicated, no any IL-1β secretion was detected.