MHC class I-like MILL molecules are beta2-microglobulin-associated, GPI-anchored glycoproteins that do not require TAP for cell surface expression.
Kajikawa M, Baba T, Tomaru U, Watanabe Y, Koganei S, Tsuji-Kawahara S, Matsumoto N, Yamamoto K, Miyazawa M, Maenaka K, et al. J Immunol. 2006 Sep 1; 177(5):3108-15.