IL15 and colorectal cancer: To investigate the in vivo antitumor efficacy of probiotically delivered IL-15 in combination with PTT, we established a subcutaneous Colon26 colorectal cancer model in BALB/c mice and followed the treatment schedule outlined in Figure 4A. The tumor temperature in PBS-injected mice experienced only minor changes (within 5°C) following 10 min of irradiation (Figures 4B and 4C).