The hER cDNA was amplified by RT-PCR method from breast cancer cell, MCF-7, according to the sequence of human full-length of estrogen receptor cDNA. The gene was cloned into the yeast expression vector via pGEM-T/hER vector, which was transformed into Saccharomyces cerevisae. And then Western blot and immunohis-tochemistry methods were used to assay the expression of hER cDNA in the yeast cell. The result showed that hER cDNA was expressed successfully in yeast cell,so as to construct the yeast system to e...