TGM2 and lung cancer: Concerning NSCLC, two in vivo studies on a patient cohort [113,114] suggested TG2 as a biomarker of increased invasion/migration and poor prognosis, highlighting significantly increased TG2 expression in lung cancer tissues compared to normal ones and showing a correlation between TG2 upregulation and shorter disease-free survival in the non-adenocarcinoma subtype in a Korean cohort [113] and in both the non-adenocarcinoma and adenocarcinoma cancer subtypes in Chinese patients [114,115].