DHTKD1 and neoplasm: In order to examine the in vivo effects of AdARET and AdAREF using a tumor xenograft model, HeLa cells were implanted into the hind flanks of nude mice and the tumors that developed were injected twice with 109 vp AdARET, AdAREF, or dl312, which is an E1A gene-deleted type5 adenovirus [23], as a control.