Cardiac Cre-recombinase and FKBP12 levels. (A) Cre⁺ levels in hearts from 1-wk-old male mice (n = 6 for each genotype). (B) FKBP12 levels in hearts from 1-wk-old male mice (n = 3). (C) Cre⁺ levels in hearts from 3-mo-old male mice (n = 6 for each genotype). (D) FKBP12 levels in hearts from 3-mo-old male mice (n = 14, 7, 4, and 14 for FL, MCK-FKD, MHC-Cre⁺, and MHC-FKD, respectively). (E) Cre⁺ levels and FKBP12 levels in hearts from 6-mo-old-male mice. (n = 4 for FL, MCK-FKD, and MHC-FKD, n = 2 for MHC-Cre⁺ only). (F) Cre⁺ levels and FKBP12 levels in hearts from 3-mo-old female mice (n = 6 for FL, MCK-FKD, and MHC-FKD. (G) Relative mRNA levels for FKBP12 and FKBP12.6 in MHC-Cre⁺ and MHC-FKD mice. (n = 3 for each). (H) MHC-Cre⁺ per total proteins in hearts of hemizygous MHC-Cre⁺ mice from Hamilton lab (H-MHC-Cre⁺) versus hemizygous mice from Jackson Laboratories (B6.FVB-g(Myh6-cre)2182Mds/J, which we designate J-MHC-Cre⁺), n = 3, 3-mo-old. In all panels, the levels of proteins were assessed by western blotting with representative western blots shown at the left in each panel. Proteins of interest were normalized to the total protein level in the same lane, normalized to the average expression level in FL hearts and expressed as %FL. Data were analyzed with one-way ANOVAs and P values indicated. Data are plotted as the mean ± SD. Source data are available for this figure: SourceData F1.