SKAP2 and infection: Notably, when SapS-Spot expressing SA564 ΔsapS cells were used to infect RAW 264.7 macrophages, the majority of SapS-Spot was detectable in macrophage lysates at 3 and 5 h post infection (Figure 2B), suggesting that SapS is primarily secreted into the phagolysosome and/or cytosol of the S. aureus loaded immune cells.