Previous studies have shown that HER2 and HER3 heterodimerize and form the predominant and most potent mitogenic combination in carcinoma cells [31–33], hence we investigated whether these particular effects of exogenous palmitate on HER2/neu-positive SKBR3 breast cancer cells are able to increase the efficacy of trastuzumab treatment. The gene discussed is ERBB3; the disease is breast carcinoma.