In relation to the discrepancies in the observed therapeutic effects of MSC.sTRAIL vs. MSC.FL-TRAIL, they are reconcilable by the fact that in lung cancer models MSCs with FL-TRAIL might work very well, as most systemically administered MSCs will infiltrate the lungs in the first 24–48 h, before they are cleared and appear in other tissues including tumours, but in far smaller numbers [75]. The gene discussed is TNFSF10; the disease is lung carcinoma.