Although the Δ17–19 transcript had an in-frame deletion, a recent study demonstrated that the expression of the human BRCA1 alternative splicing variant, Δ17–19, in the MCF-7 cells resulted in an impaired assembly of DNA repair complexes and aberrant DNA damage response (25), thus contributing to an increased risk of developing cancer in the carrier subjects. This evidence concerns the gene BRCA1 and cancer.