CSL Limited is BioTechnology company headquartered in Melbourne, Australia. CSL Limited has around 22,000 employees as on 2018. CSL has acquired a number of companies. They include: Aventis Behring, which is now known as global biotech leader CSL Behring, U.S. plasma collector Nabi, which helped to form the world's premier plasma collection company in CSL Plasma, the Novartis influenza vaccine business, now integrated and known as Seqirus, the world's second largest influenza vaccines company and Calimmune, a leader in gene-modification and cell delivery technology. As on 2018 they had 22000 employees.