MKI67 and endometriosis: Using IHC, Kim et al. examined the expression of VEGF with an array of other markers such as CD44, matrix metalloproteinase-2 (MMP-2) and Ki-67 in endometriosis [44], and reported that VEGF is present in both glandular epithelium (100%) and stromal cells (81.8%) of the DE lesions; however, there was no statistically significant difference compared to other types of endometriosis.