We then co-cultured Pmel+ Teff cells with gp100-expressing B16 mouse melanoma cells (B16-gp100; Fig. 1d), and we co-cultured GD2-CAR T cells with LAN-1 human neuroblastoma cells (Extended Data Fig. 1d), in conditioned medium for 4 h to minimize the impact of the conditioned medium on tumour-cell viability and proliferation, and the killing of tumour cells was assessed34. Here, PMEL is linked to melanoma.