EEF1A1 and fibrous dysplasia: If the EF1α-tTA portion of the R26(EF1α-tTA/TetO-mCh-Rs1) construct was capable of regulating TetO activity in vivo, we would predict that the TetO-Rs1 x R26(EF1α-tTA/TetO-mCh-Rs1) mice would show symptoms reminiscent of McCune-Albright syndrome including embryonic lethality, fibrous dysplasia of the bone, short stature, hormonal disturbances, and skin pigmentation defects [45].