(A) Relative mRNA of Arg1 in the remote (RA) and infarct area (IA) of FoxO4 KO and WT littermate mouse hearts post-MI 1 day as measured by qRT-PCR. mRNAs were normalized against internal GAPDH (n=6). *, p<0.05. (B) Western blot of Arg1 from tissues described in (A) (n=3). *, p<0.05. Protein levels were quantified by densitometry and normalized against GAPDH. (C) Immunofluorescent micrographs of IA from histological heart sections of FoxO4 ecKO and control littermates stained with Arg1 antibody post-MI day 2. Arg1 immunofluorescence from 5 different sections of each genotype mouse was quantified by Image-J, and averaged values are shown (n=3) *, p<0.05. Scale bar=100μM. (D) Arginase activity of lysates from remote area (RA) and infarct area (IA) of FoxO4 ecKO or control littermates (n=3). *, p<0.05.