Interestingly, the prophage ΦSa3 harbors the immune evasion cluster (IEC) genes that can favor the persistence of the SCV during infection, with 3 genes promoting immune evasion: chp (chemotaxis inhibitory protein of S. aureus; CHIPS), scn (staphylococcal complement inhibitor; SCIN), and sak (staphylokinase) (Fig. 1D) (18, , –21), suggesting that phage activation in the SCV may be promoting persistent infection through enhanced expression of these factors. This evidence concerns the gene SRI and infection.