CD44 and breast cancer: Many genetic factors contribute to tumorigenesis and progression of BC [6, 7], such as mutations in both TP53 and FGFR3 genes [8–9], as well as alterations in the expression of genes involved in cell morphology, epithelial-mesenchimal transformation (EMT) and apoptosis resistance [10], such as CK genes [11], CD44 [12], E-cadherin [13] and Survivin [14].