For example, in breast cancer, MUC1 and CD44 overexpression facilitate tumour-EC interactions and promote TEM (Rahn et al., 2005; Wang et al., 2005; Yu et al., 2007; Zen et al., 2008), with MUC1 overexpression linked to poor prognosis (Jing et al., 2019). This evidence concerns the gene MUC1 and breast cancer.