The CD44 variant isoforms (CD44v3, CD44v6, CD44v8, etc.), absent in normal tissues, seem to be restricted to aggressive tumors and have crucial roles in the regulation of stemness, self-renewal, tumor initiation, metastasis, and chemoresistance (Zeilstra et al., 2014; Chanmee et al., 2015). This evidence concerns the gene CD44 and neoplasm.