Analyses of IL-1β expression in microglia following exposure to HIV-1SF162 showed induction of full length IL-1β (p31) by 4 hr post-infection increasing by 24 hr post-infection at which time the processing of IL-1β could be observed in the appearance of a 29 kD band, representing the first of two cleavage events that are required for the maturation of the cytokine [43,44] (Figure 3C). Here, IL1B is linked to infection.