Survival and VCN 4 months after GT with transduced lin− cells or transduced wm cells. The recipients were conditioned with either 0 cGy or 200 cGy and either remained on ERT long term (4 months), short term (1 months), or not at all. (A) Survival. Solid lines are as follows: −NoERT: 0−NoERT lin− (n = 9), 0−NoERTwm (n = 7), 200−NoERT lin− (n = 13), 200−NoERTwm (n = 8). Dashed lines are as follows: +1mERT: 0 + 1mERTlin− (n = 7), 0 + 1mERTwm (n = 4), 200 + 1mERTlin− (n = 7), 200 + 1mERTwm (n = 4). Dotted lines are +4mERT: 0 + 4mERTlin− (n = 7), 200 + 4mERTlin− (n = 11), 200 + 4mERTwm (n = 10). Survival was decreased with no conditioning compared with 200 cGy TBI (P < .0001). (B) Percent survival at day 120. *Survival with no conditioning and no ERT (0−NoERT) after infusion of transduced lin− or transduced wm cells was significantly decreased compared with all others (P < .01). **Survival in 200−NoERTlin− mice was significantly less than 200 + 1mERTlin− or 200 + 4mERTlin− mice (P < .05). (C) VCNs in cell suspension of tissues analyzed 4 months after GT: 200−NoERTlin− (n = 5), 200 + 1mERTlin− (n = 6), 200 + 4mERTlin− (n = 11), 200−NoERTwm (n = 8), 200 + 1mERTwm (n = 4), or 200 + 4mERTwm (n = 10; means ± SEM). *Spleen VCN is significantly greater in 200−NoERTwm compared with 200−NoERTlin−, 200 + 1mERTlin−, 200 + 4mERTlin−, and 200 + 4mERTwm (P < .05). **Marrow VCN is significantly greater in 200 + 1mERTwm compared with 200 + 1mERTlin− (P < .05).