CAV1 and neoplasm: Importantly, the response of PC3(−) xenograft tumors to radiation treatment was significantly less pronounced when they were co-implanted with Cav1-silenced HS5(−) fibroblasts compared to co-implantation with Cav1-expressing HS5(+) fibroblasts as demonstrated by the increased time to reach a four-fold tumor volume (Fig. 4A) (PC3(−)HS5(+) 0 Gy: 13, 9 ± 0, 90 d, n = 10; PC3(−)HS5(+) 10 Gy: 21, 75 ± 1.29 d, n = 8; PC3(−)HS5(−) 0 Gy: 10, 89 ± 0, 35 d, n = 9; PC3(−)HS5(−) 10 Gy: 12, 90 ± 0, 94 d, n = 10).