Cytotoxicity of rApxIIIA-containing crude toxin preparation towards PBMCs from a set of mammalian species. The fraction of PI-positive cells was measured by flow cytometry after a one-hour exposition to 50 μl RPMI-1640 (mock), 5 μg rApxIIIA or PAF 10%. Values are means ± SDs from three representative experiments. Asterisks: species-specific values significantly different from corresponding mock-exposed value (P < 0.05). Po, Sus scrofa domesticus Piétrain; Wb (wild boar), Sus scrofa scrofa; Bo, Bos taurus; Cap, Capra hircus; Llama, Lama pacos; Hu, Homo sapiens; Dog, Canis familiaris; Mu, Mus musculus; Rat, Rattus norvegicus.