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.

 We report on a case of a 43 - old - male with a bronchogenic cyst in the distal esophagus , which was misdiagnosed as a malignant esophageal tumor based on preoperative imaging and high levels of the tumor markers CA 19 - 9 and CA 125 .
CA 125

 Penicillamine - induced myasthenia gravis associated with antibodies to acetylcholine receptor .
acetylcholine receptor

 Our data indicate that the various subunits of the human P - TEFb complex may play distinct roles at multiple stages to mediate Tat activation of HIV - 1 transcription elongation .

P - TEFb