“…While there have been numerous reports of HLA-DR expression by melanomas [ 21 , 55 – 58 ], cervical [ 59 – 62 ], ovarian [ 63 – 68 ] prostate [ 19 , 69 – 73 ], liver [ 74 – 77 ], kidney [ 18 , 78 ], bone [ 79 ], breast [ 80 – 85 ], esophageal [ 86 – 89 ], head and neck [ 90 – 92 ], bladder [ 93 – 96 ], colorectal [ 97 – 101 ], lung [ 102 – 105 ], pancreatic [ 106 ], larynx [ 107 – 109 ], gastric [ 110 – 113 ], glioma [ 114 – 116 ], and thyroid [ 117 – 120 ] cancers, these MHC class II proteins have not been adequately evaluated as potential targets in the treatment of non-hematological cancers. Although it is not entirely clear why tumors derived from tissues of non-lymphoid origin express HLA-DR, the predominant theory for which there is a great deal of experimental support suggests this expression can be initiated in response to tumor infiltration by lymphocytes, macrophages or dendritic cells [ 84 , 96 ] and the release of cytokines [ 84 , 121 ] during the inflammation that often accompanies tumor growth and the progression of the disease.…”