The steric hindrance-mediated inhibition of TCR and peptide-MHC engagement by MUC21 allows cancer cells to evade T cell mediated immune surveillance, which may help explain why MUC21 is expressed in incohesive-type lung adenocarcinoma [26] that is prone to metastasis [27, 38]. The gene discussed is HLA-C; the disease is lung adenocarcinoma.