Comparative analyses of folate receptor (FR)-positive and -negative cells revealed that FRi-ExNC caused a stronger decrease in Cyclin D/Cdk4 and anti-apoptotic protein Bcl-2, as well as a higher increase in the growth arrest regulating protein p21WAF1 and pro-apoptotic protein PARP-1, in FR-enriched cancer cells. Here, PARP1 is linked to cancer.