Signage is displayed at the Pfizer Inc. Kendall Square Research and Development Center in Cambridge, Massachusetts, U.S., on Monday, Nov. 23, 2015. Pfizer Inc. and Allergan Plc agreed to combine in a record $160 billion deal, creating a drugmaking behemoth called Pfizer Plc with products from Viagra to Botox and a low-cost tax base. Photographer: Scott Eisen/Bloomberg