FIG. 4.

Signaling pathways required for HBEGF inhibition of apoptosis. The apoptotic indices were calculated in HTR-8/SVneo (A) or SW.71 (B) cell lines after exposure to H/R in the absence (striped bars) or presence (stippled bars) of 1 nM HBEGF, with kinase inhibitors (black bars) or the corresponding inactive structural analogues (white bars), as indicated. Significance was determined with reference to the apoptosis index observed in control cells cultured continuously at 2% O₂ (dotted line). Values represent the average ± SEM of at least three experiments; *P < 0.05.