In the beginning, it was thought that even though SLAM was identified as a cellular receptor for Morbilliviruses, the infection of MeV in SLAM negative epithelial cells of the trachea, bronchial tubes, lungs, oral cavity, pharynx, esophagus, intestines, liver, and bladder indicated that entry of MeV is mediated by other cellular receptors [49]. The gene discussed is SLAMF1; the disease is infection.