Reigning Timico Gold Cup champion Sizing John leads 38 early entries for this year's Cheltenham showpiece on March 18.
Jessica Harrington's charge will aim to become the first horse since Best Mate, who won the big race three times in a row between 2002-04, to retain the Gold Cup in March.
Sizing John is among an 18-strong Irish contingent for the race with stablemate Our Duke also included at this stage, while 32Red King George winner Might Bite is likely to contend for Nicky Henderson, who also has stablemate Whisper.
Last year's second and third, Minella Rocco and Native River, are both included at this stage again for Jonjo O'Neill and Colin Tizzard respectively, while other familiar Cheltenham names in the running for the Gold Cup include Cue Card and 2015 winner Coneygree.
Betfair Chase winner Bristol De Mai and Becher Handicap Chase victor Blaklion lead Nigel Twiston-Davies' chances of glory in the race, while Willie Mullins will aim to break his Gold Cup duck in 2018 as he hopes one of Acapella Bourgeois, Bachasson, Djakadam, Killultagh Vic and Total Recall will come out on top.
Tizzard has previously ruled out Thistlecrack from the race, while Yorkhill, who was thought to be under consideration by Mullins, has not made the list.
