illumina inc ilmn stock gained 47 premarket on monday after the company announced sunday that its board had accepted the resignation of francis desouza as ceo effective immediately the company named charles dadswell senior vice president and general counsel as interim ceo and desouza will stay on in an advisory capacity until the end of july the company said in a release the leadership change comes in the wake of illumina’s battle with activist investor carl icahn who sought to add three of his candidates to the board and unseat the illumina chairman and ceo illumina shareholders voted in late may to elect one of icahn’s nominees and did not reelect the chairman john thompson