SOCS2 and in situ carcinoma: It was observed that IC50 values of CIS for P13L0.15O1.5D2C2, D2C1, and D1C2 were 6.70, 14.50, and 4.41 ng/mL, which were 0.018, 0.29, and 0.04 times lower than the IC50 of CIS for those corresponding dose combinations of DTX2/CIS2, DTX2/CIS1, and DTX1/CIS2 (360.93, 50.13, and 117.74 ng/ml), respectively.