There are over 79 medical device manufacturing companies in Baja California which represent more than half of the industry's presence in Mexico. Around 620,000 workers (over 50,000 in Tijuana) make the region the largest industry concentration in North America. The state is also a leading hub for medical device manufacturing and the headquarters for the public-private alliance. Medical Device Cluster of the Californias and the Cali-Baja Biotech Cluster which represents over 800 companies and includes San Diego, Imperial Valley and Baja California.