in the miniseries ": heroes and martyrs", gambit was revealed to be the clone of mister sinister, created from sinister's own pre-mutated dna. sinister wished to destroy his master, apocalypse, and to do so he needed a body that had not been subject to apocalypse's altering. he then engineered mutant powers for the clone, using the dna of cyclops. this technically makes him the third summers brother; in that alternative reality. however, apocalypse learned of sinister's plan and had the child stolen and left it in the care of the thieves guild.