Table 1. The number of FIR hetero and homo knockout mice during the time of observation.

	FIR+/+	FIR+/−	FIR−/−	supposed FIR−/−
Time at obervation	Wild mice	FIR hetero knockout mice	FIR homo knockout mice	Dead embryo	Total
At birth	12	17	0	0	29
E13.5 to E14.5	9	20	0	6	35
E9.5	5	11	0	6	22
Total	26	48	0	12	86