(Left) At the normal condition, which Ups1, Tam41 and Pgs1 are present, PA transported by the Ups1-Mdm35 appears to be predominantly used to produce CL. (Right) The simultaneous loss of Ups1 with either Ups2, Tam41 or Pgs1 may activate alternative PA transport and/or CL synthetic routes, resulting in restored CL accumulation. Red broken lines indicated speculative PA transport and CL synthetic routes.