SERPINE1 and head and neck squamous cell carcinoma: Although bladder urothelial carcinoma and testicular germ cell tumors do not show differences in PAI1 expression between normal and tumoral tissues, it is significantly increased in other cancers including stomach adenocarcinoma, head and neck squamous cell carcinoma, esophageal carcinoma or thymoma (The Cancer Genome Atlas (TCGA); [13]).