CD44 and cancer: Given that TNBC aggressiveness and mortality is correlated with high CD44 expression [57], and previous therapeutic strategies which target TGFβ and CD44 signalling axes have shown promise yet with adverse side effects [40,58], along with the potential for rapid translational update of rhPRG4 for clinical evaluation, rhPRG4 represents an ideal candidate as a potential biological anti-cancer therapy.