n.等位基因；对立形质
名词allele的复数形式.
There can be more than two alleles for a gene. 一个基因可能有两个以上的等位基因。
Risk from both alleles was confined to estrogen receptor-positie tumors. 两种等位基因引起的乳腺癌仅限于雌激素受体阳性肿瘤。
