TRIM21 and lung cancer: Analysis of The Cancer Genome Atlas (https://portal.gdc.cancer.gov/) database showed that, compared with matched nontumor tissues, downregulation of TRIM21 mRNA was frequently observed in lung cancer (60 of 109), and overexpression of TRIM21 mRNA was frequently observed in kidney clear cell carcinoma (49 of 72), stomach cancer (11 of 32), and head and neck squamous cell cancer (14 of 43) (Supplemental Figure 5).