Rom 16:21-23 form a sort of postscript with greetings from Paul’s companions in Corinth. Timothy was with Paul in Macedonia (2Co 1:1) before he came to Corinth. Lucius may be the one mentioned in Act 13:1. Jason was once Paul’s host (Act 17:5-9) in Thessalonica, Sosipater may be the longer form of Sopater of Act 20:4. They are all Paul’s fellow-countrymen (suggeneis).