. Evidence was accumulating in support of the concept that toxicity did not correlate with enzymatic phospholipids hydrolysis (see for example Condrea et al., 1981). The publication of Kini and Evans proposed a unifying concept to explain the pharmacolog- ical activities of venom PLA2s. The model hypothesized that the action of PLA2s is based on protein–protein interactions instead of on protein–phospholipid interactions, as previously believed. The authors proposed that toxic PLA2s have a ‘pharmacological site’ in their surface, which is distinct from the catalytic site. Such molecular region, which differs among various PLA2s, binds with high affinity to a ‘target site’ constituted by a protein in the plasma membrane of a target cell. Once bound to its target protein, the PLA2 could exert its action either by a catalytically-dependent process, i.e. by hydrolyzing phospholipids in the membrane or, alternatively, by enzymatically-independent mechanisms that affect cellular functions. In the case of damage secondary to enzymatic phospholipid hydrolysis, the deleterious actions on cells could be due to the products of the reaction, i.e. lysophospholipids and fatty acids. The model therefore explained the difference between specific and non-specific effects of PLA2s, the former based on protein–protein recognition, and the latter on overt phospholipid hydrolysis.