TCF7L2 and lung cancer: However, later a report showed an association between NLK (Nemo-like kinase), a member of the protein kinase (serine/threonine) superfamily, and TCF4 (T-cell factor 4), a transcription factor substrate for NLK in case of lung cancer that revealed that NLK expression was found to be negatively correlated with the expression of TCF4 in lung cancer advancement [93].