CD163 and endometriosis: In the early phase (2–3 weeks) after endometriosis induction, iNOS + M1 macrophages showed an ascending trend before CD163 + macrophages began to accumulate at 4–5 weeks [15], which interestingly coincided with some clinical studies that M1 macrophage markers were enriched in the early stages of endometriosis [10, 16].