sentences:  NBS1 has a role in microhomology-mediated end joining (MMEJ) repair of double strand breaks.It is one of 6 enzymes required for this error prone DNA repair pathway.NBS1 is often over-expressed in prostate cancer, in liver cancer, in esophageal squamous cell carcinoma,
  in non-small cell lung carcinoma, hepatoma, and esophageal cancer, in head and neck cancer, and in squamous cell carcinoma of the oral cavity.