Normoxic and Hypoxic tumor Growth; Time to Achieve 100 mm3. Normoxic and Hypoxic tumor xenografts were established in the mammary fat pad of female nude mice and tumor growth was monitored until 100 mm3 tumors were achieved. The tumor size was measured every other day using Vernier calipers in two dimensions. Individual tumor volumes were calculated using the formula volume = [length × (width)2]/2 where the length was the longest diameter and the width was the shortest diameter perpendicular to length. For each group, n = 6. Each data point represents the mean ± SD.