POU5F1 and endometrial cancer: Conversely, consistent with our previous data, OCT4A and OCT4Bv transcripts were undetectable or expressed at very low levels in MCF7, a non-aggressive cancer cell line (Fig. 2b) [16], suggesting that the expression of these OCT4 transcripts is positively correlated with the aggressiveness of breast and endometrial cancer cells, which is inconsistent with a previous bioinformatics analysis [24].