Of these two failed American gene therapy cases, one involved a patient suffering from the so-called "boy in the bubble" immunodeficiency disease, in which immunity genes were introduced using retroviruses. But the researchers didn't realize that the genes would spread around. The genes entered the 11th chromosome, activating the adjacent leukemia gene, leading to leukemia.
美國兩名基因治療失敗案例，一位是俗稱「泡泡兒」的免疫缺乏症病童，利用反轉錄病毒將免疫基因帶入，沒想到基因會「亂跑」，跑到 11 號染色體、引起白血病的基因旁，結果引發白血病。