Studying renal transplant patients, Muslin likens the integration of the acquired kidney into the body image to the process of identification. He follows this integration through the 'foreign body stage', where the new organ is perceived as ego-alien, to complete incorporation into the body image. There is then total loss of awareness of the new organ and a gradual cathexis of the new organ with narcissistic libido to the point of complete inclusion within the self. In addition, the new organ becomes symbolic of many developmental conflicts and serves as a representation of key object relations.