Foreman gives House the Senator's latest results. He's negative for all those weird hairy cell viruses, meaning that he doesn't have hairy cell leukemia. Foreman also takes a second to express his shock that his self-absorbed ass of a boss would make a pride-swallowing speech to save their jobs. This is the kind of gratitude House appreciates, so he gives Foreman a "you're welcome," and then notes that the Senator is positive for Epstein-Barr. Foreman says that doesn't have anything to do with hairy cell leukemia, but apparently it has something to do with something, as House hands off the chart and run-limps into the Senator's room.
House removes the mask from the Senator's face and asks him for the real story behind that tongue scar. In between gasps for air, the Senator begs House to give him back his oxygen mask. House says he knows (somehow) that the tongue scar came from the Senator biting it during a childhood seizure, and House needs to know what medication the Senator used to take to control his epilepsy. The Senator just says that he hasn't taken any seizure medicine since he was ten, so the voters shouldn't be scared that one of their presidential candidates will be all doped up or having seizures during an important world conference or whatever. House yells at him to cut the political spinning bullshit and tell him what the medicine was before he suffocates. The Senator screams that it was phenytoin. House replaces the oxygen mask and soothingly tells the Senator that he'll be okay, even though he's a LIAR. Surely there must have been a better way to get that information from him than attempted murder.
House tells everyone how that phenytoin caused the Senator's problems, being sure to use those sports metaphors Cameron hates. In his zeal to annoy her, though, House's football metaphor falls apart as he is forced to give the Senator's body two metaphorical quarterbacks. Ha! Anyway, the Senator has common variable immunodeficiency disease, which Chase points out is an immunoglobulin deficiency, which he suggested earlier. House says that when Chase said it, it was stupid, but that when House said it, after the benefit of the Senator's going into respiratory distress and the positive Epstein-Barr test, it was smart. That's what you get for tattling, Chase. The Senator got Epstein-Barr at some point in his life -- probably childhood -- but it didn't surface until he was really stressed out, like running for president. Although one would think that the senatorial race and his wife's dying from cancer would have also been sufficiently nerve-wracking, but I guess not. Anyway, phenytoin and Epstein-Barr together can cause the CVID, although I'm not sure how, exactly, they all got together thirty or forty years ago but are only just wreaking havoc now. I guess the football metaphor went over my head as well as Cameron's. I'm so ashamed. House orders some IV immunoglobulin, which we can all hope works out better than the last time it was administered, and says it'll either cure the Senator, or he'll die.