A pSUPER RNAi system was used to construct a RING3-deficient cell line and research on the relationship between RING3 and Cyclin A.Marked expression of Cyclin A was detected when serum-starved NIH/3T3 stimulated with serum.Once RING3 knocked down
it has a same effects on the Cyclin A expression.The Cyclin A transcription is controlled by both RING3 and E2F-1.The deduction that RING3 relates to tumorigenesis can be partly explained by the expression of Cyclin A.