A study investigated whether vascular hemangioma cells originated from fetal or maternal tissue. Fluorescence in situ hybridization (FISH) techniques were used to determine maternal XX cells in male XY tissue in 4 specimens of infantile hemangiomas from boys. In a single case of infantile hemangioma, a single XX female (probably maternal) cell was detected. All other cells from this male in addition to the 3 other specimens were negative for XX cell detection. Endothelial cells from infantile hemangiomas likely derive from the child itself (Regnier, S. et al. Br J Dermatol 2007, 157(1): 158-160).