​ With transgenic technology, additional pieces of DNA  is inserted into a new gene of plant to direct the activity of that gene . to turns the gene on, one of these pieces is the "promoter" .The most widely used promoter is the cauliflower mosaic virus 35S promoter, often abbreviated as the CaMV promoter or the 35S promoter. There is a concerns that the CaMV promoter might be harmful if it were to invade our cells and turn on our genes. This is because this promoter was obtained from the virus that causes cauliflower mosaic disease in several vegetables, such as cauliflower, broccoli, cabbage, and canola.


  Eventhough there are other promoter that has been used in developing crops, the abundant production of the transgenic protein in a wide variety of situations make CaMV promoter is often chosen. Thus, these characteristics seen as advantages in transgenic technology. Consequently,  the CaMV promoter might be harmful if it were to invade our cells and turn on our genes. However, there have been no tests to determine whether the CaMV promoter has invaded human tissues or whether fragments of it would include enough of the genetic code to function as a promoter.