<prompt> Gene affected in breast cancer?WT1p53RASp83  <response>: Ans. is b i.e., p53 Most common gene involved infamilial breast cancer - BRCA-1 Most common gene involved in sporadic breast cancer -p53 Most common gene involved overall Hereditory plus sporadic - p53 Maximum increase in susceptibility to breast cancer is seen with - p53 mutation 90 whether it is sporadic or Hereditary. 