Table 1. Strain-dependent survival of Anp32b-deficient mice. Mendelian ratios of Anp32b heterozygote intercrosses from six-generation (A) FVB/N and (B) BALB/c congenic backgrounds.

	(A) FVB/N Congenic				(B) BALB/c Congenic
	Anp32b genotype				Anp32b genotype
	+/+	+/–	–/–		+/+	+/–	–/–
Expected	62	123	62		83	167	83
Observed	92	148	6		102	181	50

(A) Chi-square test: P < 10^-15, (B) Chi-square test: P < 10^-4.