We found that the coexistence of Tet2 deletion and the Kit D814V mutation was insufficient to confer IL-3 independency to BMMCs (data not shown), suggesting that additional genetic alterations are required for transformation of these cells in vitro, or that the transforming requirement for these cells in vitro might differ from those required to generate a mast cell disease in vivo. This evidence concerns the gene KIT and maculopapular cutaneous mastocytosis.