Rob Liefeld worked on the series 'New Mutants', later called 'X-force'.X- force's first issue, was the single largest selling issue of a comic ever. : r/xmen
X-Force Omnibus by Rob Liefeld & Fabian Nicieza, Vol. 1 (Review/Retrospective) | the m0vie blog
Rob Liefeld X-Force #1 Double-Page Spread 18-19 Original Art | Lot #92162 | Heritage Auctions