Sequential activation of PK-C and PTK. The cells were treated for 1 hour with 1 nmol/L of the PK-C activator PMA or pretreated for 15 minutes with the specific PTK inhibitor genestein (37 μmol/L) or the inactive genestein analog daidzen (39 μmol/L), followed by the PMA treatment. The autoradiographic (A) and graphic data (B) are presented as previously described.