For example , if the epo gene cannot be shut off properly by the athlete ' s own biological mechanisms , his or her blood is likely to begin to thicken as it is bulked out with excess red blood cells , triggering strokes or heart attacks 比如,如果运动员自身的生理机能不能很好地清除epo基因,他或她的血液会由于过多的红血球凝聚而变得粘稠,并因此导致中风或者心脏病的发生。