Citryll was founded by Helmuth van Es, and Renato Chirivi of ModiQuest B.V., CSO of Citryll and co-inventor of tACPA. ModiQuest B.V. and Citryll’s antibody development program is based on the unexpected discovery of immunoglobulins with anti-inflammatory activity in immunoglobulin repertoires of rheumatoid arthritis patients. Its lead molecule CIT-013 is currently being produced by Lonza and first in man studies have started in 2021.