Migne, Patrologia Gracca 24, columns 529–605, prints a work of Eusebius which he entitles Eusebii Caesariensis Commentarii in Lucae Evangelium quantum superest in Codicibus Vaticanis, the text of which is that of Angelo Mai, Bibliotheca Nova Patrum iv. 159ff., published in 1847. The work is abstracted from the big Lucan catena of Nicetas of Heraclea, other parts of which were published separately by Mai. No mention of a Commentary on Luke is made by later patristic writers such as Jerome and Photius in their notices of work by Eusebius, and J. Quasten, Patrology iii, does not include it in his description of Eusebius' work. Mai, however, is confident, I believe rightly, that it is a genuine work of Eusebius.