MKI67 and myocardial infarction: Recent single cell (sc)‐RNA sequencing of murine neonatal myocardial infarction (MI) hearts revealed crucial regulatory networks governing heart regeneration.[14] Therefore we analyzed the data with accession No. GSE130699.[14] This single nucleus RNA‐sequencing dataset identified a unique immature CMs population enriched with genes of the immature heart (Tnni, Myh7, and Actc1), cell‐cycle progression (Aurka, Ccnb1, Ki67, Cdk1, and Cdk4), anti‐oxidant genes (Prdx1, Sod1, Sod2, and Cat), glycolysis (Tpi1 and Aldoa) and reduced maturation genes (Myh6, Ryr2 and Cacna1c).