The untreated LA7 breast tumor bearing rats (Group II) revealed intensive staining of PCNA and Ki-67 (Fig. 6), whereas, the vernodalin treated animals (Group III and IV; low and high dose respectively) exhibited a substantial decrease in the numbers and intensity of cell proliferation markers such as Ki67 and PCNA, comparable to a standard drug, Tamoxifen (Group V). Here, PCNA is linked to breast neoplasm.