EGFR and cancer: The cytotoxic activity of anti-cancer agents against ES-2 monolayer and spheroids, an in vitro model of peritoneal metastasis, was compared using cisplatin (a platinum drug, CDDP), paclitaxel (a tubulin inhibitor, PTX), SN-38 (a topoisomerase I inhibitor, an active metabolite of CPT-11), and PD153035 (an EGFR inhibitor).