part of nephron development cell proliferation involved in kidney development extraglomerular mesangial cell proliferation GO:0072122 2010-02-22T01:42:23Z biological_process The multiplication or reproduction of extraglomerular glomerular mesangium cells by cell division, resulting in the expansion of their population. Extraglomerular mesangial cells (also known as lacis cells, Goormaghtigh cells) are light-staining cells in the kidney found outside the glomerulus, near the vascular pole and macula densa. Goormaghtigh proliferation lacis cell proliferation mah