CD44 and breast cancer: In mammary cancer the CD44-ICD is engaged in EMT-related transcription factor expression and nuclear translocation, particularly of Oct4 and Sox2 (Cho et al., 2015) In glioma CIC, the CD44-ICD is engaged in hypoxic state maintenance via binding HIF2α, which enhances HIF target gene activation at perivascular oxygen tension (Johansson et al., 2017).