POU5F1 and lung cancer: Consistent with tumour‐suppressive function, OCT4 has been shown to suppress the metastatic potential of BCCs via Rnd1 down‐regulation, while OCT4 overexpression leads to the up‐regulation of E‐cadherin expression, even in BCCs with high E‐cadherin levels.5 Conversely, OCT4 is also believed to facilitate cancer progression by increasing BIRC5 and CCND1 expression in hepatocellular carcinoma.38 OCT4 promotes drug resistance and metastasis in lung cancer by regulating downstream PTEN and TNC genes.8 The human OCT4 gene generates three variants.