The experimental validation of DNA damage clustering induction, as well as, the repair mechanisms involved have not been an easy task. There are some discrepancies that can still be found between experimental evidence or data and prediction models using Monte Carlo (MC)-based methodologies . Significant advancement in the understanding of expected clustered DNA damage induction mechanisms has been achieved using a fast and cell-level MC code, the Monte Carlo Damage Simulation (MCDS) code, integrated into the general-purpose MC N-particle radiation transport code system (MCNP) . At the same time, a better understanding of the processes and mechanisms involved in the repair of clustered DNA lesions has been provided by the development of analytical biochemical models for DSB and base lesion repair .