Effect of SLT-1 on the viability of human breast cancer cell lines. The percentage of cell viability of 8 breast cancer cell lines based on the SRB dye binding assay was measured as a function of toxin concentration. Cell viability curves are shown for CAMA-1 (□), JS-1 (⧫), MCF-7 (▪), MDA-MB-231 (▴), MDA-MB-468 (○), MDA-MB-469 (•), SKBR3 (▵), and T47D (◊).