A, Results of qRT-PCR for circNF1 in MKN28 and HFE145 cells without or with exogenous overexpression of circNF1. B and C, WST-1 proliferation assay results in MKN28 and HFE145 cells transfected with either circNF1 (CircNF1) or empty vector (EV) at day 0, 1, 3 and 5. Proliferation increase at day 5 in cells treated by exogenous circNF1 overexpression. (p=0.0128 and p=0.0181, respectively). D, Representative images for colony formation after transfecting circNF1 or EV. *, p<0.05; ***, p<0.001.