The co-administration of curcumin and NAC continued to demonstrate a reduction in Smooth Muscle Actin (ACTA2) and Proliferating Cell Nuclear Antigen (PCNA) in IPF-F as compared to untreated control, however the expression of Collagen 1A1 (COL1A1) and Cyclin D (CCND1) was not significantly altered. The gene discussed is PCNA; the disease is idiopathic pulmonary fibrosis.