On transfer of TPEX isolated from B16-OVA melanoma into new tumour-bearing mice, Miller et al. found that TCF-1+ SLAMF6+ TIM3- TPEX could both self-renew and give rise to SLAMF6+ TIM3+ and SLAMF6-TIM3+ progeny over 14 days, adding to the model of a phenotypic spectrum among TTEX [85]. Here, TCF7 is linked to melanoma.