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.

Example Input:  Free protein S deficiency in acute ischemic stroke .
Example Output: protein S

Example Input:  This enhancer element functioned in a position - and orientation - independent manner both on the Pax - QNR P0 promoter and the heterologous thymidine kinase promoter .
Example Output: thymidine kinase

Example Input:  In further support of the biological significance of these DNA - protein interactions , the IL2RA oligonucleotide from - 291 to - 245 proved to be sufficient in either orientation to confer PMA inducibility to the mitogen - insensitive thymidine kinase gene promoter in Jurkat cells .
Example Output:
thymidine kinase