In ERα+ BCs, compared to normal samples, the sixth exon of the collagen type VI alpha 3 chain coding gene (COL6A3) involved in an ES event (COL6A3_5_6_7_ES) exhibited a significantly higher inclusion level in tumor samples (dPSI = 0.49; p < 0.0001). This evidence concerns the gene COL6A3 and neoplasm.