MCC mouse xenograft treatment groups and experimental outline.

<p><b>A</b>) NSG mice were subcutaneously injected in the right flank with 2x10⁷ MCV-positive, MCC cells (MKL-1, MS-1, WaGa, or MKL-2). <b>B</b>) NSG mice were monitored for palpable tumors (~2mm x 2mm) to determine start of treatment. <b>C</b>) Mice with palpable tumors were randomly assigned to either saline treatment, YM155 treatment for 3-weeks at 2mg/kg, YM155 continuous treatment at 2mg/kg, or YM155 continuous treatment at 4mg/kg. Each week of treatment consisted of a single intraperitoneal injection per day for 5 days, followed by 2 days of rest.