(A) While the structural core of LECA NPC — its inner and outer rings — can be convincingly traced to type I and type II coat proteins (left), it is yet unclear how the NPC acquired its other components — responsible for mRNA processing and general permselective function (right). As individual FG-nups/transport factor combinations were shown sufficient to execute partial per-selective function, and POMs — to form pores in lipid bilayers, the possibility arises that these components formed a separate simple pore before incorporation into NPC. (B) Summary of principal variations and evolutionary events in NPC architectures post-LECA. Principal architectural changes are named for each compartment. Principal evolutionary events are named and indicated. Paralogous duplication events indicated by a — a,b pairs with slight colour change. Gene loss — by dashed lines and letters. Gene gain — by a — c pairs and colour change. Changes in stoichiometry — shown schematically. Principal complex gains are named.