ALDH1A1 and lentivirus infection: E‐cadherin expression was knocked down in NSCLC cells with six2 knockdown via lentivirus infection, qRT‐PCR and Western blot confirmed the knockdown efficiency and knockdown of E‐cadherin rescued the inhibition of six2 knockdown on the expression of stemness markers (ALDH1 and Nanog) (Figure 6A‐D).