The following is a personal account of this work by Philip Rosenberg: “I am pleased that this paper was selected for inclusion in the special issue of Toxicon since the problems we faced and the pitfalls we had to avoid are relevant to those which new investigators will face regardless of their field of study. When I began these studies there was disagreement and confusion as to whether the enzymatic activity of phospholipases correlated with their pharmacological properties. I had the good fortune of finding a field of research which was interesting to me and one where new methods could lead to more definitive conclusions. I immediately realized it was inappropriate to measure enzymatic activity in vitro under artificial conditions and attempt to relate these results to in vivo pharmacological effects. Studies were carefully performed but the results were irrelevant to the question they were attempting to answer. I also knew I had to test pharmacological effects under many different conditions in which enzymatic activity would vary markedly. I therefore carried out many different chemical modifications of both highly toxic and relatively non-toxic snake venom phos- pholipase enzymes, testing their effects on enzymatic and pharmacological properties. The carbamylation of lysines, as described in this paper, was one of these studies. These were, however, wide ranging studies requiring expertise in organic and analytical chemistry, biochemistry, pharmacology, toxicology, etc. My advice to young investigators, therefore, is to seek out, as I did, collaborators who can supplement your expertise and from whom you can learn. The excitement of science lies in never knowing where your research pathways will lead; be alert for opportunities. I branched out to using presynaptically acting phospholipase toxins as tools in studying protein phosphorylation and the mechanism of neurotransmitter release in brain synaptosomes”.