EGFR and ovarian cancer: To assess whether stimulation of ovarian cancer cell proliferation by SPINK1 is dependent on EGFR signaling, we next evaluated proliferation of CAOV3 and OVCAR3 cells treated with rSPINK1 in the presence or absence of erlotinib, a small molecule drug that selectively targets the ATP binding site of the EGFR kinase domain [21].