eLife assessment
This study provides an important demonstration of how the false-positive rate of high-resolution 2D template matching to find particles of a given target structure in 2D cryo-EM images (2DTM) relates to overfitting the data towards the template. The authors present new methods to measure the amount of model bias that gets introduced in high-resolution features of such maps, with compelling evidence that high-resolution features that are not present in the template can still be reconstructed in 3D from images obtained by 2DTM. The paper could be strengthened by the inclusion of a more elaborate discussion (and possibly additional experiments) to describe the limitations of 2DTM for smaller target structures.