1. To identify genes that are improperly regulated following exposure to low-dose ionizing radiation in knockout transgenic mice that have no SATB1genes.
   
2. To better understand the mechanisms underlying individual susceptibility to low dose radiation.

Individual susceptibility will be studied Using SATB1 knockout mice. These mice are hypersensitive to single exposures of very low dose radiation. SATB1 is a global gene regulator in thymocytes and is essential for T-cell development. Without SATB1, thymocytes show a significant delay in the DNA repair process. Therefore, DNA repair could be impaired in the absence of SATB1.

1. Identification of genes that are improperly induced or fail to be induced after radiation of SATB1 knockout mice.
   
2. Better understanding of the genetic basis underlying individual susceptibility to low dose radiation.