In moyamoya disease, what is meant by "intimal thickening"? are the cells proliferating, or are they just growing larger without division?

Proliferating: They appear to be proliferating at an increased rate leading to narrowing and eventual blockage of the artery. May be an association with an abnormality in Ring Finger Protein 213 (RNF 213) gene according to what I was able to research. See link below for info on function of the gene. http://www.ncbi.nlm.nih.gov/gene/57674 Hope this was helpful. Dr R