Earlier this year , a study by gerd pfreier of beckman research institute pointed out the specific substance causing cancer in cigaret smoke , whose target was some parts of gene which , people discovered , played a prominent role in some cancers 而今年早些时候，贝克曼研究所的格尔德?普法伊费尔所作的一项研究确切地指出了卷烟烟雾中固有的致癌物，这些致癌物袭击的目标是一种基因的某些部分，人们已经发现，这种基因在一些癌症中很突出。
