YAP1 and hepatocellular carcinoma: (1) Transcriptional regulation: Key transcription factors, such as FOXM1 (notably in hepatocellular carcinoma), SP1 (in prostate cancer) [23], the YAP/TEAD complex (in oesophageal squamous cell carcinoma) [24], and E2F family members [25, 26], directly bind to the KIF4A promoter, activating its transcription.