Exon 7 of CEACAM1 was skipped in one of the breast cancer patient subpopulations, CEACAM1-S1, yet was preferentially included in normal breast from TCGA, normal breast tissue from GTEx, and in several normal tissues such as lung, liver, heart, brain, blood, and adipose tissue (Fig. 5B and fig. This evidence concerns the gene CEACAM1 and breast cancer.