Fig. 2

Tumor incidence in syngeneic mice resulting from injection of MM cells, either parental (no treatment; NoRx) or cells surviving γ-ray irradiation (RT). AB12 (a, b) and RN5 (c, d) cells were irradiated with 15 Gy γ-ray; surviving cells were used for s.c. injections in the right flank of mice (n = 5/group). The number of injected cells are indicated on the graphs. Surviving irradiated AB12 or RN5 cell injection resulted in the same tumor incidience with 10-fold less cells than when injecting the untreated AB12 or RN5 cells. The same results were obtained at two different doses of injected cells. e, f Start of tumor development was considered, when tumors become palpable; measurements of the two maximum perpendicular diameters were used to calculate the tumor size