In this report, we observed that in a series of patients with R/R DLBCL treated with CAR-T, early administration of G-CSF was associated with reduced febrile neutropenia without any impact on the toxicities, CRS or neurotoxicities, as well as on the efficacy and expansion of CAR-T in term of response. This evidence concerns the gene CSF3 and congenital rubella syndrome.