我们曾以ｐＳＶ２ｎｅｏ作为共转染质粒观察到ＮＦＩＬ６具有转化基因活性。本文以ｐＭＥＳｘ１（含ｎｅｏ抗性基因）质粒作为共转染质粒，发现能表达有义ＮＦＩＬ６的ＮＩＨ３Ｔ３转染子，可同时出现转化形态的克隆和扁平形态的克隆，二者比例６∶４，且ＮＦＩＬ６的表达状态相似。我们提出，ＮＦＩＬ６在ＮＩＨ３Ｔ３细胞表现为转化基因活性时，作用方式具有随机性。本文还提出，ｐＳＶｎｅｏ可能是ＮＩＨ３Ｔ３细胞内在不稳定性的促进因素 We used pSV2-neo as a co-transfection plasmid to observe that NF-IL6 has transforming gene activity. In this study, pMESx1 (containing neo resistance gene) plasmid was used as a co-transfected plasmid. It was found that NIH3T3 transfectants that express sense NFIL6 can present both transformant and flat form clones. : 4, and the expression of NF-IL6 is similar. We propose that NF-IL6 has a random mode of action when NIH3T3 cells exhibit transforming gene activity. This paper also proposed that pSVneo may be a contributing factor to the intrinsic instability of NIH3T3 cells.