Effect of phenylhydrazine injection. (A) Mean hematocrit ± SD after a single dose of phenylhydrazine of 0.2 mg /g. A total of 4 mice for each genotype was used. (B) Survival after phenylhydrazine treatment. A single dose of phenylhydrazine of 0.23 mg/g was intraperitoneally injected and mice were monitored for 7 days; 20 animals per genotype were used.