We kinetically analyzed RNA interference(RNAi)for lamin A/C in HeLa cells,assuming suppression and recovery phases of gene expression,and dilution of transfected small interfering RNA(siRNA)by cell divisions.We observed the inhibitory effect of RNAi over a period of 6 days using various siRNA concentrations,and the maximum gene silencing efficiency occurred at Day 2 or 3.The gene silencing efficiency as a function of time and siRNA concentration was further quantitatively evaluated using a kinetic analysis method,demonstrating that RNAi for lamin A/C can be understood as a conventional drug response system.This work provides potentially important guidelines for future applications using nanomater ials as delivery vehicles of siRNA in RNAi for lamin A/C.