tc Most mss (א2 C D F G Ψ 1739 1881 𝔐 latt sy co) have ἐθνῶν (ethnōn, “of the Gentiles”) after “teacher.” The shorter reading has poorer external credentials (א* A I 1175 pc), but is preferred because ἐθνῶν probably represents a gloss added by copyists familiar with 1 Tim 2:7. There is no easy explanation for the omission of the word if it were original here.