For patients with HER2 over-expressing breast cancer who did not receive trastuzumab, the risk of relapse was greater for patients with membranous PRPF38B positive disease than those with membranous PRPF38B negative disease [HR (95% CI) = 1.65 (1.07–2.53); p = 0.02] (Figure 4A(i)). This evidence concerns the gene PRPF38B and breast cancer.