Synergistic anti-tumor effect of Taxol and SS1P. A, Treatments were begun when A431/H9 tumors reached 120 mm3 (n = 5). Taxol was given at 50 mg/kg 5 days after implantation. SS1P was given at 0.2 mg/kg on days 6, 8 and 10. Controls received saline. (●), control; (◯), Taxol alone; (▾), SS1P alone; (▵), combination treatment. B, Shed mesothelin levels in tumor ECF (Ba) and serum (Bb) were measured 4 days after Taxol treatment (n = 5). C, The effect of Taxol on SS1P-Alexa staining of A431/H9 tumors. Mice with A431/H9 tumors (150 mm3) were treated with Taxol at 20 or 50 mg/kg (n = 5). SS1P-Alexa (20 μg) was injected. The control group received saline. Black, saline; grey, Taxol at 20 mg/kg; white, Taxol at 50 mg/kg. *, P < 0.05; ** P < 0.01.