H,I. C-circle analyses in the indicated cell lines 72 h after treatment with siPOLD3 or siLuc used as control for transfection. Quantifications are shown below (n=3). siSMARCAL1 was used as positive control for increased C-circle production in cells with defective fork reversal activity (Zhang et al, 2019b). Data information: All scale bars: 5 μm. Data are shown as mean ± SD. 