There are also several protein biomarkers that have been linked to the moyamoya disease diagnosis. Although the sample size of the studies performed are small due to the rarity of the disease, the findings are indicative of a correlation between the disease and several specific protein biomarkers. Other studies have confirmed the correlation of moyamoya and adhesion molecule 1 (ICAM-1) being increased as compared to normal vascular function counterparts. Furthermore, it has been concluded that the localization of inflammatory cells suggests that the inflammation stimulus iteself may be responsible for the proliferation and occlusion in the ICA, ACA, and MCA found in those with moyamoya disease.