[1][4] Plexin also has implications in development of other body systems by activating GTPase enzymes to induce a number of intracellular biochemical changes leading to a variety of downstream effects.

[3] Highly conserved intracellular domains consisting of a bipartite segment which functions as a GTPase-Activating Protein (GAP).

[7][13] These GTPases can have a number of downstream effects, but in particular to Plexin expressed on axonal growth cones, the concentration the secondary messenger cyclic guanosine monophosphate (cGMP) increases within the cell.

[citation needed] C-class plexins have fewer structural Methionine-Related Sequences (MRS) and IPT domains.

[15][16] Genetic knockout of plexins have shown to be lethal at embryonic stages due to severe developmental defects in body systems regulated by semaphorin-plexin signaling.