(A) Schematic of experimental procedure to induce immunological memory against tumor-derived SIY. All mice were housed for equal times and were 6–8 weeks of age at the beginning of the experiment. Mice were treated with TAM 2 months after complete rejection of the primary MC57-SIY tumor. At day 24 post-TAM treatment, tumor growth of the autochthonous tumor was assessed until the experimental endpoint was reached. (B–D) Growth of tumors in naive or MC57-SIY immunized BP-SIY (B), BPC-SIY (C), and BP (D) mice as shown in (A). Given are mean with SEM, significance was determined using a two-sided Anova test, n = (B) 4 and 7, (C) 4 and 8, (D) 4 and 4 (naive/immunized) pooled out of two independent experiments. Significance was assumed with p ≤ 0.05, with ** ≤ 0.01; **** ≤ 0.0001. See also Figure S1.