Methylcarbamyl PAF C-16 is a stable analog of PAF C-16 with a half-life greater than 100 minutes in platelet poor plasma due to its resistance to degradation by PAF-AH. It is nearly equipotent with PAF C-16 in its ability to induce platelet aggregation both in isolated platelets and in platelet-rich plasma. In NRK-49 cells overexpressing the PAF receptor, both PAF C-16 and methylcarbamyl PAF C-16 cause the induction of c-myc and c-fos and the activation of mitogen-activated protein kinase. Methylcarbamyl PAF C-16 induces G1 phase cell cycle arrest, suggesting a potential role for PAF in the inhibition of oncogenic transformation.