Infantile hemangioma’s curious biological behavior of rapid growth and slow regression entices researchers and clinicians alike. Basic investigative techniques have progressed well beyond traditional light microscopy and hematoxylin/eosin staining. The three phases of hemangioma’s life cycle (proliferation, involution, and involuted) have been examined using immunohistochemistry to portray protein expression and PCR-based differential display, in situ hybridization and microarray to quantitate mRNA expression. The major cellular phenotypes on stage of the hemangiomatous drama have been indentified by flow cytometry and further studied in tissue culture. A murine model has exposed a subpopulation of hemangioma stem cells and has been used to determine the mechanism of drug treatments. Molecular genetic studies given strong evidence that hemangioma begins as a somatic mutation in a primitive cell type.