Extron 1-5 of RHO gene was amplified by polymerase chain reaction (PCR), and the mutation of RHO gene was screened by direct DNA sequence measurement.

The NPR1 gene was amplified from Arabidopsis thaliana genome DNA by DNA-PCR method. The DNA sequenced analysis showed that the sequence of amplified NPR1 gene was the same as the published sequence.

Conclusion the four gene fragments were amplified from known genes involved in cell proliferation and differentiation, while the one unknown gene fragment maybe from a new functional leukemia gene.