Comparison of mean C/N ratio values in open clusters for stars at different evolutionary stages with theoretical models. The red dots denote the mean values for RGB stars, the blue dots indicate the RC stars, and the green crosses represent the RGB stars above the luminosity bump (the scatter is presented when is available). The solid red line shows the predicted C/N ratios after 1DUP (Charbonnel et al. 2017). The solid blue line indicates the minimum C/N values predicted by models including thermohaline mixing (Lagarde et al. 2017). The dashed line corresponds to the model that includes both thermohaline- and rotation-induced mixing (Charbonnel et al. 2017).