Glioma-associated oncogenes (GLIs) are zinc finger protein family members and downstream regulatory factors of the classic Hedgehog (Hh) signaling pathway. GLI proteins influence the growth and development of organisms and aid in tissue repair. However, aberrant expression of the GLI family member GLI1 promotes carcinogenesis by inducing epithelial–mesenchymal transition (EMT), angiogenesis, and other signaling pathways. Overexpression of GLI1 is thought to be an indicator of poor prognosis as well as a potential therapeutic target for cancers. GLI inhibitors such as zerumbone, GANT61, resveratrol, and cyclopamine depress the Hh pathway in vitro and in vivo cancer research, and other non-canonical pathways may also activate expression of GLI1. Here, we summarize GLI function in carcinogenesis and cancer-targeted therapy.