AXL and melanoma: Upon evaluating the single-cell transcriptional program from 19 metastatic melanoma tumours, Tirosh et al. identified a rare therapy-resistant subpopulation of melanoma cells expressing high levels of AXL Receptor Tyrosine Kinase inside the heterogenous tumours harbouring MITF (microphthalmia-associated transcription factor) due to clonal selection after targeted treatment with RAF/MEK inhibition [34].