instruction:
In this task, you are given a sentence. You are expected to recognize the name of gene or protein. Although there might be several correct answers, you need to write one of them.
question:
 Ultraviolet - B - induced DNA damage is repaired by the nucleotide excision repair mechanism very efficiently .
answer:
- B


question:
 The transcriptional events that control T cell tolerance to peripheral self Ags are still unknown .
answer:
peripheral self Ags


question:
 The gene encoding the cytolytic protein perforin is selectively expressed by activated killer lymphocytes .
answer:

cytolytic protein