Ex vivo treatment of tumor cells with pairs μ-21-ON/μ-155-ON and μ-155-ON/μ-17-ON did not affect the proliferative potential of RLS40 tumors (Figure 6e,f), while for cocktails μ-21-ON/μ-17-ON and μ-17-ON/μ-155-ON/μ-21-ON, the number of PCNA-positive cells reached 35.0 ± 6.9% and 21.8 ± 1.3%, respectively, meaning that more than a 2–3-fold decrease in the proliferative activity of tumor cells in comparison with controls was achieved (Figure 6e,f). This evidence concerns the gene PCNA and neoplasm.