Twenty-four of the leading biotechs maintain operations in the country.

With the exception of Celgene, of the world’s top 25 largest (by market capitalization) public biopharmaceutical and biotech companies, 24 have a facility in Ireland. About two decades ago some 50 companies dotted the Irish landscape, but that number has grown to over 300.

Johnson & Johnson, the world’s largest biotech has been in Ireland for 80 years — the company employees approximately 3,000 employees across multiple sites, including Janssen operations in Cork and Dublin. Similarly, Pfizer has been in the country since 1969 and has seven locations with 3,300 employees. The company has invested more than $7 billion in Ireland, and as recently as 2014 spent $30 million on a new lab.

Another big investor in Irish operations is MSD, with 50 years in the country. The company has invested some $2.5 billion on facilities and infrastructure to maintain its footprint. MSD produces more than 60% of its top 20 products in Ireland and has announced it plans to create 330 new jobs, investing more than $280 million over the next three years at two of its sites.

Other notable players in Ireland include Amgen, Abbvie, Allergan and Eli Lilly & Company. Amgen will spend approximately $300 million to revamp a Pfizer facility acquired in 2010, which included engineering new sterile syringe fill-finish capacity at the Dún Laoghaire site. AbbVie also stands out, with five sites in the nation, including three manufacturing facilities. In January, the company announced it had entered into an alliance with start-up Genomic Medicine Ireland to map the genomes of 45,000 Irish citizens. Allergan has had a presence in the country for approximately 40 years, employing nearly 1,700 people. Allergan confirmed earlier this year it was investing more than $42 million to improve operations. Another player, Eli Lilly & Company, has been in Ireland since the 1970s and claims a manufacturing site in Cork.