Estrogen Resistance or Estrogen Insensitivity Syndrome (EIS) is an extremely rare intersex variation only known to affect six individuals so far. Individuals with estrogen resistance have defective estrogen receptors (ER) that cannot achieve their goal. This variation effects both CTM and CTF individuals alike. CTM individuals with this variation are shown to be infertile with low sperm count, a micropenis or cryptorchidism, unusual and low hair growth, and underdeveloped organs. CTF...