Mutations in LMNA encoding lamins A and C are associated with at least 10 different degenerative disorders affecting diverse tissues, collectively called laminopathies. A recent study showed that mis-accumulation of SUN1 underlies the pathology of degenerative features in laminopathies, and concomitantly suggests a gain-of-function versus a loss-of-function model for the action of lamin A mutants.