Table 1. Sf1 deficiency reduces incidence of germ cell tumors. TGCT incidence in Ter mice deficient for Sf1.

Ter/+; Sf1+/- mice were intercrossed with Ter/+ mice (illustrated in Supplementary Fig.3). Progeny were of genotypes listed in the table. Progeny were genotyped and the testes phenotypes examined. The significance of the difference in tumor incidences between the Ter/Ter and Ter/Ter;Sf1+/- strains is P = 0.0174. Differences in the tumor incidences of Ter/+ compared to Ter/+;Sf1+/- and +/+ compared to Sf1+/- were not statistically significantly.

Genotype	No. with tumors	Bilateral tumors	Unilateral tumors	Sterile testes	Normal testes	No. of males examined
Ter/Ter	17 (77%)	12 (71%)	5	5 (23%)	0	22
Ter/Ter; Sf1+/-	10 (40%)	4 (40%)	6	15 (60%)	0	25
Ter/+	23 (45%)	5	18	0	28	51
Ter/+; Sf1+/-	21 (40%)	4	17	0	32	53
+/+	0	0	0	0	20	20
+/+; Sf1+/-	1 (5%)	0	1	0	21	22