Reframing gene essentiality in terms of adaptive flexibility. - Gabriela I. Guzmán; Connor A. Olson; Ying Hefner; Patrick V. Phaneuf; Edward Catoiu; Lais B. Crepaldi; Lucas Goldschmidt Micas; Bernhard O. Palsson; Adam M. Feist (BMC Syst. Biol., 2018)