MET
MET / c-Met receptor — the molecular target that 1 compounds in the wiki act on.
In one line: A "build new connections" receptor in the brain that the peptide dihexa targets.
MET (the c-Met receptor) responds to a growth factor that, in the brain, drives the formation of new synapses — the connections behind learning and memory. The experimental peptide dihexa is reported to supercharge this in animals, making it a striking (but entirely unproven-in-humans) nootropic.
As with any "growth" pathway, there's a built-in caution: signals that grow new connections can, in principle, also help tumours grow. No human safety data exists.