CD44 and breast carcinoma: Indeed the fact that some studies suggest a relationship between expression of CD44 standard or its variant isoforms with respect to prognosis (40–42), while other reports are less clear as to a relationship between CD44 and outcome (43–46) is likely due to the complexities of the CD44 expression pattern and the ability to clearly differentiate between different isoforms; our data further point to the importance of understanding the complexities of CD44 variant expression rather than CD44 per se in breast cancer.