Gaius Helvius Cinna    (the Social Set of Catullus)
Neoteric Poet and friend of Catullus.
Catullus praises his Zmyrna. in Poem 95.
May have been in Bithynia with Catullus (57-56 B.C.)
Follower of Caesar, but was lynched by a mob after Caesar's assassination in 44 B.C., because they mistook him for a different Cinna.  
Poems referring to Cinna as a friend and a poet:
Poem 10VARVS me meus ad suos amores
Poem 95ZMYRNA mei Cinnae nonam post denique messem
Poem 113CONSVLE Pompeio primum duo, Cinna, solebant