PAR-2 proliferative responses to synthetic peptidomimetics. BaF3/PAR-2 or BaF3/PAR-2^{Arg36 → Ala36} (mutant) cell lines were incubated with progressive concentrations of PAR-2–derived (PAR-2^39-44) (A) or TR-derived (TR^42-47) (B) peptidomimetics, essentially as described in the legend to Fig 1. As shown, both cell lines responded almost identically when activated by either TR^42-47 or PAR-2^39-44, although the responses using TR^42-47 were consistently ∼70% of those seen using equimolar concentrations of PAR^39-44. Results represent the mean ± SEM from four individual wells from a representative set of experiments completed on two occasions.