Tumor volume and eradication rate. (A) Tumor volume of re-challenged parental CT-26 cells. Animals that were treated with CDDP and one (single) or three (multiple) injections of HVJ-E/BLM were intradermally re-challenged with 5 × 106 parental CT-26 cells on day 10 after CDDP administration (arrow). The initial (upper) and re-challenged (lower) tumor volumes per mouse were assessed (mean value ± standard deviation). p < 0.05, single vs multiple injection, Student's t test. The control mice were age-matched mice that were intradermally inoculated with CT-26 cells. (B) Eradication rate of initial or re-challenge tumor. On day 31 after CDDP administration (on day 16 after re-challenge) the tumors – whether visible or invisible – were examined.