To investigate the effects of SIWA318H treatment on PSN1 tumors we examined the expression of alpha smooth muscle actin (αSMA), a fibrosis marker, and p16INK4a, a cellular senescence marker, in tumor tissues harvested from mice treated with either isotype control antibody or LD SIWA318H using immunostaining. The gene discussed is CDKN2A; the disease is neoplasm.