FHIT and lung adenocarcinoma: APOBEC mutagenesis may also be increased in case of reduced expression or the loss of protein activity of the tumor suppressor fragile histidine triad protein (FHIT), and higher levels of APOBEC mutagenesis were observed in TCGA lung adenocarcinoma tumors that had both increased APOBEC3B expression and the loss of FHIT protein expression [7, 9, 32].