The increase in proinflammatory macrophages seen in endometriosis patients 4 is reminiscent of the elevated ratio of M1/M2 macrophages occurring in autoimmunity, in opposition to expanded M2 populations associated with allergic asthma and tumor proliferation and invasion.[56] IL1 signaling could feasibly be involved in the pleiotropic associations observed. This evidence concerns the gene IL1A and endometriosis.