GLI1 and gastric cancer: Studies have revealed that GLI1 not only participates in the tumorigenesis of GC, but also upregulates CSC surface markers such as CD44, Lysine-specific demethylase 1 (LSD1) and SRY-Box Transcription Factor 9 (Sox9) [151,152], whereas GLI2 fosters the expression of CSC-related genes, such as CD44, Nanog homeobox (Nanog) and octamer-binding transcription factor 4 (Oct4), by inducing platelet-derived growth factor receptor beta (PDGFRB) [153,154].