Further, Based on microarray analysis of RA and IH exosomes, we discovered that miR‐106a‐5p, transferred to the macrophages through exosomes, participated in this mechanism by promoting M2 macrophage polarization via down‐regulating PTEN and activating the STAT3 signaling pathway in vitro and in vivo. Here, STAT3 is linked to isolated hemihyperplasia.