PTEN and breast cancer: Also, a reduced or absent of PTEN expression in breast cancer tissue was only in 28 out 85 of breast cancer patients (33%) in the Engin et al., (2006) study, which was using IHC for the detection of PTEN. There were other studies did not correspond to our data in this study, and reported decreased or absent PTEN expression in breast carcinoma tissue in high percentage among the breast cancer patients (Kechagioglou et al., 2014; Gschwantler-Kaulich et al., 2017; Shabbir et al., 2017).