AFAP1 and cancer: LncRNA actin filament associated protein 1 antisense RNA1 (AFAP1-AS1) is upregulated and acts as an oncogene in a variety of cancers, such as hepatocellular carcinoma, esophageal carcinoma, pancreatic ductal adenocarcinoma, colorectal cancer, cholangiocarcinoma, gallbladder cancer, and nasopharyngeal carcinoma [27–36].