Table 1.

Incidence of myeloid leukemia and survival in experimental mice

Experimental groups	No. of mice	No. of leukemic mice	Incidence of leukemia, % ± SE	Onset of leukemias, days	Mean survival, days ± SE
CC	165	3	1.8  ±  1.1	320	788.1  ±  14.5
3C	163	37	22.7  ±  3.3	330	674.7  ±  12.7
CRA	135	0	0	—	832.6  ±  18.4
3RA	131	14	10.7  ±  2.7*	468	773.6  ±  17.0
CRB	70	0	0	—	805.9  ±  25.0
3RB	76	6	7.9  ±  3.1*	689	713.5  ±  25.6

^*χ² tests for the incidence of myeloid leukemia were performed. Statistically significant differences were found between 3RA and 3C (P < 0.02) and 3RB and 3C (P < 0.01).