Consistent with the PCR array data, the transcriptional expression of Bcl-2, an anti-apoptosis factor, was markedly decreased in the testis of asthma mice, while the mRNA transcription of pro-apoptosis genes including Bax, BNIP3, caspase-9 and AIF were enhanced significantly in asthmatic testis (Fig 7B). Here, CASP9 is linked to asthma.