HIPK2 and lung cancer: Besides, Several reports linking CtBP with p53-independent cell death in vitro[27], [36], [37] : (i) targeting of CtBP by ARF (alternate open reading frame) results in p53-independent apoptosis; (ii) HIPK2 (homeodomain interacting protein kinase 2) mediates CtBP phosphorylation and degradation in UV-induced cell death; (iii) UV triggered active JNK1 (c-Jun N-terminal kinase 1) promotes apoptosis by phosphorylated and down-regulated CtBP in human lung cancer cells.