CHRNA5 and lung cancer: The same applies to another three genes KLF6 (Krüppel-like zinc finger transcription factor) [23], MSH5 (MutS protein homolog 5) [24] and ACTA2 (Alpha-smooth muscle actin) [25], which were also found to be associated with lung cancer by several previous GWASs, albeit not as prominently as CHRNA5 and TERT.