Because we have previously reported that the medium of co-cultures of TAM and CAF with NB cells contains high levels of total and active TGF-β1 (1785.1 ± 29.9 and 896.2 ± 61.3 SEM pg/ml, respectively) [18], to test whether TGF-β1 could be responsible for the drug resistance observed in the presence of TME cells, we performed experiments (with three cell lines) in the presence of Galunisertib, a TGF-βR1/ALK5 inhibitor, added to the co-cultures of NB and TME cells. Here, TGFB1 is linked to neuroblastoma.