CD44 and neoplasm: Several studies have reported a positive role of TGF‐β in the CSC population by promoting or sustaining stemness.43, 44, 45 Although it is not clear how expression of the CSC markers CD44 or CD44v9 is regulated, activation of the EMT program by TGF‐β at the TIF may contribute to tumor stemness, and this tumor microenvironment may increase the expression of CD44v9 expression at the TIF.