Under the patronage of the Custodian of the Two Holy Mosques King Salman bin Abdulaziz Al Saud, the Global Center for Mass Gathering Medicine at the Ministry of Health in cooperation with Al-Faisal University will hold its 3rd international conference here tomorrow, on Monday with the participation of 39 speakers from 12 countries. The Ministry of Health said that the three-day conference will be attended by a large number of experts and scientists from around the world and many international and regional organizations and institutions.