ERBB2 and breast ductal adenocarcinoma: RNAs fromtrastuzumab-responsive SKBR3 cells, a widely employed in vitro tumor modelcharacterized by naturally occurring HER2 gene amplification, HER2 receptor proteinoverexpression, and HER2-dependency for cell proliferation and survival [18, 56, 57], and trastuzumab-refractory JIMT1 cells, a HER2 gene-amplified cellline established from a ductal carcinoma pleural metastasis of a 62-year-old patient who did notrespond to trastuzumab treatment ab initio [53-55], were evaluated by quantitative real-time PCR(qRT-PCR) to evaluate the expression of 84 key genes involved in autophagy (Fig. 1).