CD44 and neoplasm: Interestingly, elevated circulating HA protects against melanoma lung metastasis.63 Given that HMM-HA inhibits YAP-mediated tumor growth through CD44 and that LMM-HA enhances YAP-mediated tumor growth by binding to CD44,59 increased circulating HA after Stabilin-2 ablation may be due to the tumor-suppressive properties of HMM-HA.