ABCB1 and malignant colon neoplasm: As shown in Figure 2, the rank order according to the MDR1/β-actin ratio in the colon cancer cell lines is as follows: Colo320HSR (0.90) > SNU-C4 (0.45) > HCT-8 (0.26) > SNU-C1 (0.12) > HCT-116 (0.11) > LoVo (0.10) > DLD-1 (0.07) > SNU-C5 (0) = HT-29 (0).