TACSTD2 and neoplasm: Ninety-six hours after transfection of ErbB3 SMARTpool siRNAs, tumor cells from CRC cultures were harvested and again probed for levels of EGFR activation, experiments which showed elevated levels of Trop2 and reduced levels of p-EGFR even when ErbB3 was incompletely suppressed (Fig. 3c).