Altered expression of estrogen receptor-α variant messenger RNAs 		 between adjacent normal breast and breast tumor tissues 

Using semiquantitative reverse transcription-polymerase chain 			 reaction assays, we investigated the expression of variant messenger RNAs 			 relative to wild-type estrogen receptor (ER)-α messenger RNA in normal 			 breast tissues and their adjacent matched breast tumor tissues. Higher ER 			 variant truncated after sequences encoding exon 2 of the wild-type ER-α 			 (ERC4) messenger RNA and a lower exon 3 deleted ER-α variant (ERD3) 			 messenger RNA relative expression in the tumor compartment were observed in the 			 ER-positive/PR-positive and the ER-positive subsets, respectively. A 			 significantly higher relative exp