WASL and infection: Consistent with the idea that SopA prevents Cdc42-N-WASP signaling from inhibiting invasion, WT S. Tm invasion of WT MEFs ectopically expressing SopA (Figure S4E) continued to occur steadily 30-120 min after the start of infection (Figure 4D), as seen above for ΔsopE2 entry (Figure 3A).