It has also been demonstrated that CEACAM5 (Iqbal et al., 2017; Powell et al., 2018), CEACAM6 (Maraqa et al., 2008; Tsang et al., 2013; Iqbal et al., 2017; Rizeq et al., 2018), and CEACAM19 (Michaelidou et al., 2013; Estiar et al., 2017) are overexpressed in breast cancer and are associated with enhanced tumor invasiveness and metastasis. Here, CEACAM6 is linked to breast cancer.