John.

Acts 12:12, 25
And when he had realized this, he went to the house of Mary the mother of John, also called Mark, where many people were gathered together praying. . . .

Acts 13:5, 13
When they arrived at Salamis, they proclaimed the word of God in the Jewish synagogues. And John was with them as their helper. . . .

Colossians 4:10
My fellow prisoner Aristarchus sends you greetings, as does Mark the cousin of Barnabas. You have already received instructions about him: If he comes to you, welcome him.

2 Timothy 4:11
Only Luke is with me. Get Mark and bring him with you, because he is useful to me in the ministry.

Philemon 1:24
as do Mark, Aristarchus, Demas, and Luke, my fellow workers.