Of the MDR1-positive sections, weak staining (1+) was found in 21% (20 of 96) (Figure 3C), moderate staining (2+) in 44% (42 of 96) (Figure 3F) and strong staining (3+) in 35% (34 of 96) in primary tumours, whereas weak staining (1+) was found in 20% (8 of 40), moderate staining (2+) in 35% (14 of 40) and strong staining (3+) in 28% (11 of 40) (Figure 3I) in metastatic lesions. This evidence concerns the gene ABCB1 and neoplasm.