“All of them
καὶ ἀφέντες αὐτὸν ἔφυγον πάντες.
This is similar to Matthew, chapter 26:56. Luke, chapter 22, and John, chapter 18, did not say anything about all the apostles fleeing, but it might be presumed. Mark said that all the disciples went away or deserted Jesus (καὶ ἀφέντες αὐτὸν). They all escaped or fled from Jesus (ἔφυγον πάντες). Jesus had told them all earlier that night that this was going to happen.