Targeting CD44 using peptides or antibodies has drawn great attention in cancer therapeutics but challenges remain because of abundant expression of CD44 in normal tissues including bone marrow, liver, spleen, and skin (Jin et al, 2006; Marangoni et al, 2009; Masuko et al, 2012; Li et al, 2014; Jordan et al, 2015). Here, CD44 is linked to cancer.