AFAP1 and cholangiocarcinoma: Recent decades, AFAP1-AS1 has been found to be overexpressed in most types of human cancers, such as lung cancer [14,15], hepatocellular carcinoma [16,17], cholangiocarcinoma [18,19], colorectal cancer [20,21], gastric cancer [22,23], pancreatic cancer [24], esophageal squamous cell carcinoma [25], renal cell carcinoma [26], gallbladder cancer [27], ovarian cancer [28], tongue squamous cell carcinoma [29], nasopharyngeal carcinoma [30], and thyroid cancer [31].