*2.10. Vaccination-Challenge Assay*

The immunogenicity of the treated cells was assessed with an in vivo vaccinationchallenge model. Briefly, CT26 cells and 4T1 cells were treated as follows, respectively: (i) PDT1 12.2 nM or 9.01 nM with 25 J/cm<sup>2</sup> ; (ii) PDT2 31.5 nM or 19.4 nM with 25 J/cm<sup>2</sup> ; (iii) PDT3 12.2 nM or 9.01 nM with 67 J/cm<sup>2</sup> ; (iv) PDT4 31.5 nM or 19.4 nM with 67 J/cm<sup>2</sup> ; and (v) mitoxantrone (1.5 µM); and (vi) frozen-thawed. Then, 100 µL of the suspension of cells (4 <sup>×</sup> <sup>10</sup><sup>5</sup> CT26 or 1 <sup>×</sup> <sup>10</sup><sup>5</sup> 4T1 cells/mL) were subcutaneously injected into the right flank of mice. This process was repeated a second time, with a ten-day interval between vaccinations. Seven days after the 2nd vaccine, the mice were challenged with a subcutaneous graft of viable CT26 or 4T1 cells on the left flank. Following the challenge with viable CT26 or 4T1 cells, the animals were monitored for tumor onset, tumor volume evolution, and survival.
