Calico Life Sciences LLC is an Alphabet subsidiary whose mission is to harness advanced technologies and model systems to increase the understanding of the biology that controls human aging. Calico uses that knowledge to devise interventions that may enable people to lead longer and healthier lives. The company was announced on September 18, 2013 prior to the Google restructuring and was co-founded by former Genentech Chairman and CEO Arthur D. Levinson, PhD. It was incorporated into Alphabet with Google's other sister divisions in 2015. In Google's 2013 Founders Letter, Larry Page described Calico as a company focused on "health, well-being, and longevity" and the company's name additionally as a play on "California Life Company." In September 2014, it was announced that Calico, in partnership with AbbVie, would be opening up an R&D facility focused on aging and age-related diseases, such as neurodegeneration and cancer. Initially, each company will invest 500 million later on. In the same month, Calico announced a partnership with the University of Texas Southwestern Medical Center and 2M Companies regarding drug development for neurodegenerative disorders. In 2015, the Broad Institute of MIT and Harvard announced a partnership with Calico to "advance research on age-related diseases and therapeutics", a further partnership also was announced with the Buck Institute for Research on Aging. Also in 2015, Calico announced a partnership with QB3 based on researching the biology of aging and identifying potential therapeutics for age-related diseases and one with AncestryDNA based on conducting research into the genetics of human lifespan. At the end of 2017 and the beginning of 2018, Calico lost two top scientists; in December 2017 Hal Barron, its head of R&D, left for GlaxoSmithKline, and in March 2018 Daphne Koller, who was leading their AI efforts, left to pursue a venture in applying machine learning techniques to drug design.