RNA interference (RNAi) triggers and RNAi trigger conjugates for inhibiting the expression of Hif2α (EPAS1) gene are described. Pharmaceutical compositions comprising one or more Hif2α RNAi triggers optionally with one or more additional therapeutics are also described. Delivery of the described Hif2α RNAi triggers to tumor cells in vivo provides for inhibition of Hif2α gene expression and treatment of cancer.本發明係關於抑制Hif2α(EPAS1)基因之表現之RNA干擾(RNAi)觸發子及RNAi觸發子結合物。亦描述包含一或多個Hif2α RNAi觸發子及視情況選用之一或多種額外治療劑的醫藥組合物。將所描述之Hif2α RNAi觸發子遞送至活體內腫瘤細胞中使得抑制Hif2α基因表現且治療癌症。