Similarly, previous studies have shown prognostic utility of melanoma CTCs at baseline,24 while others could not find association.9,36 More recent studies demonstrated that the specific CTCs subtypes (i.e. RANK + or PDL1 + CTCs), instead of the total CTC counts, are the ones that harbour biomarker utility.9,37 Altogether, these results may indicate that the prognostic value of CTCs is highly affected by the platform used for CTC isolation and detection methodology. This evidence concerns the gene TNFRSF11A and melanoma.