Kochenderfer et al. found that higher serum levels of IL15 induced by low-dose chemotherapy were associated with higher peak CAR T-cell levels and remission in various lymphomas [13], and Hirayama et al. found that more intensive lymphodepletion was associated with higher postlymphodepletion levels of MCP-1 and IL-7, which in turn were associated with better progression free survival in non-Hodgkin lymphoma patients [14]. Here, IL15 is linked to non-Hodgkin lymphoma.