ERBB2 and endometrial cancer: Exposure of USPC1, USPC2, RL-95-2, HEC155, and SNG-II human endometrial cancer cells to lapatinib resulted in a dose-dependent reduction of phosphorylation of both the EGFR and HER2 receptor tyrosine kinases and their downstream signalling intermediates AKT and ERK (Figure 2A).