title: Corrigendum.
abstract: Pages H1237–H1250: Leone M, Magadum A, Engel FB. Cardiomyocyte proliferation in cardiac development and regeneration: a guide to methodologies and interpretations. Am J Physiol Heart Circ Physiol 309: H1237–H1250, 2015. First published September 4, 2015; doi:10.1152/ajpheart.00559.2015 (http://ajpheart.physiology.org/content/309/8/H1237.long).—Under Newborn mouse heart regeneration, the value for the increase in cell number upon Meis1 deletion is corrected as shown in boldface as follows: In fact, the cell number data indicate that Meis1 deletion induced the production of 0.2 million cardiomyocytes in less than 5 wk by an H3P as well as Aurora B fold increase of less than fourfold.