Luke 17:12-14 "Marcion excised" some material and "substituted" Lk 4:27 (Many lepers...Naaman the Syrian") in its place.
Luke 18:18-20 "the Father" added to "God" (v.19); "I know" instead of "thou knowest" the commandments (v.20).
Luke 18:31-33 Marcion "falsified...in its entirety".