Four non-peptidic organic inhibitors of stable CD4–MHC class II interactions: (i) TJU101, 5-(4-chloro-benzylthio)-3-{[(4-chlorophenyl)-2-thiazolyl]methylthiomethyl}-4-methyl-1,2,4-triazole; (ii) TJU102, 4-(4-methoxy-phenyl)-1-imidazo[2,1-B]benzothiazole; (iii) TJU103, N-(3-indoylmethylene)-isonicotinic hydrazone; (iv) TJU104, N-(2,4-dichloro-phenyl)-3-(1,2,4-triazol-1-ylmethyl)-1,2,4-triazole-5-carboxamide.