TGFB1 and myocardial infarction: However, our results confirmed that produced M2(IL-4) macrophages maintain their M2-like phenotype (in terms of expression of Arg1, Fizz1, Ym1, Tgfb1, Igf1 and Il1ra) even under a hostile, inflammatory environment in vitro as well as in vivo in the post-MI heart.