Several isoforms of the human CD44 molecule are associated with tumour progression and stemness in various cancers, such as breast cancer [19], gliomas [20,21], head and neck squamous cell carcinoma [22], pancreatic cancer [23,24], prostate cancer [25] and colorectal cancer [26,27] (Figure 1 and Table 1). Here, CD44 is linked to breast carcinoma.