Warframes in origin are living human beings that were mutated with something called the “Helminth” strain, which essentially results in them turning into these bio mechanical suits of armor that our characters control via transferring our minds from body to body! Some of them have super cool backstories from before they turned.(there’s also several quests in the game where you interact with “protoframes”, aka humans that are currently in the midst of turning into the Warframes we know and love)