请教关于Drugbank数据库格式的一个问题

如下(Drugbank数据库中的)在对某个药物的靶标进行描述时,为什么有的药物要出现两次?(比如加黑部分)
>Complement C1r subcomponent (DB00002; DB00002; DB00005; DB00005; DB00028; DB00028; DB00051; DB00054; DB00056; DB00072; DB00072; DB00073; DB00074; DB00074; DB00075; DB00078; DB00081; DB00087; DB00087; DB00092; DB00092; DB00095; DB00095; DB00108; DB00110; DB00111; DB00111; DB00112; DB00112; DB02944; DB03965)
哪位明白的人指点一下,谢谢