The twelve went out.
That all people
Καὶ ἐξελθόντες ἐκήρυξαν ἵνα μετανοῶσιν,
There is no equivalent to this saying of Mark, as he explained their mission. Mark said that the 12 apostles went out (Καὶ ἐξελθόντες). They proclaimed or preached (ἐκήρυξαν) that all people should repent, have a change of heart or a metanoia (ἵνα μετανοῶσιν), just like John the Baptist and Jesus had done. These 12 apostles were to continue the work and preaching of Jesus.