A shift from a pro-inflammatory milieu towards a pro-reparative environment in endometriosis lesions is accompanied by elevated expression of transforming growth factor β1 (TGF-β1) (Zhang et al., 2016a) and α-smooth muscle actin (α-SMA; ACTA2) (Itoga et al., 2003), which facilitate tissue healing. Here, ACTA2 is linked to endometriosis.