He was suffect consul in 150 AD with Sextus Carminius Vetus as his colleague.
His son was Marcus Gavius Cornelius Cethegus, consul in 170; who was his legatus or assistant while proconsular governor of Asia.
Olli Salomies, in his monograph on the naming practices of the Early Roman Empire, records a number of experts who thought Cethegus and his sister were not natural, but adopted children of Gallicanus.
After discussing the evidence, Salomies admits that he prefers the explanation that both "were Squilla Gallicanus' adoptive, not natural children.
"[6] That he was one of the witnesses to the Tabula Banasitana (AE 1971, 534) shows Gallicanus was still alive 6 July 177.