Diem joined the Johannesson group in July 2016 to work on transposable elements (TEs), which are mobile genetic sequences that contribute to host genome architecture, gene expression and evolution. She studied TE evolution in Neurospora and the genome defense systems such as repeat-induced point mutation (RIP), which is a silencing mechanism that mutates repetitive sequences including TEs. She characterized TEs in Neurospora species to study the evolution of RIP along Neurospora phylogeny. Currently, Diem is employed at the Department of Medical Sciences at Uppsala University, as a project coordinator.