However, we noticed that S100a4Gfp/Gfp mice contained relatively more FOXP3+ CD25+ CD4+ T regulatory cells (Fig. 2D), but this did not lead to noticeable signs of immune dysfunction and S100a4Gfp/Gfp mice developed normally and appeared healthy, with body weight comparable to that exhibited by S100A4‐sufficient mice. Here, FOXP3 is linked to immune system disorder.