Therefore, to clarify the clinical significance of intermediate-sized INDELs in breast cancer, we attempted to identify intermediate-sized INDELs in 54 cancer predisposition genes among 583 Han Chinese patients with breast cancer and identified a novel deletion–insertion in a translational variant of PTEN (also known as PTENα or PTEN-Long) in one patient. This evidence concerns the gene PTEN and breast carcinoma.