CircHMGCS1 markedly upregulates the IGF2/IGF1R/PI3K/AKT axis to regulate proliferation by sponging miR-503-5p.193 The expression of circEPHB4 was negatively associated with tumor weight, size, and metastatic foci in vivo.189 A higher level of circ0079929 predicted decreased tumor size and weight in nude mouse models.187 CircCDK13 is an important negative regulator in the development and progression of HCC.184. This evidence concerns the gene IGF1R and neoplasm.