Wang et al reported that a high CD44 expression promotes lung cancer cell metastasis in vitro and in vivo through activation of ERK–ZEB1 signaling.12Gupta et al studied the immunohistochemical expression of CD44 in esophageal squamous cell carcinoma (ESCC) and its predisposing lesions (mild, moderate, and severe dysplasia and esophagitis). Here, CD44 is linked to lung cancer.