In some cases, stem-like CTCs express both classical stem-like markers (e.g.CD44 [40, 44, 53, 54, 149–151], ABCG2 [109], ALDH1 [40, 44, 150, 151], DCLK1/Lgr5 [150], CD90 [54] and CD133 [109, 145]) as well as EMT-markers (e.g. Vimentin [109, 152], Twist [135]) reinforcing the concept that an aberrant activation of EMT-program enhances stemness properties and tumor-initiation potential of CTCs. The gene discussed is CD44; the disease is neoplasm.