CDK1 and Alzheimer disease: Studies have indicated that circRS-7 acts as an miR-7 sponge in Alzheimer’s disease [19] and Parkinson’s disease [20], thereby modulating the expression of downstream genes such as cyclin B1 (G2/mitotic-specific) and CdK1 (cyclin-dependent kinase 1), which suppresses cell proliferation and cell migration [21].