IGF1 and mesothelioma: Mesothelioma-initiating cells were selected from human primary samples by culturing the cells in HAM F12/DMEM medium supplemented with 1% PS, 20 ng/mL of EGF, 20 ng/mL of β-FGF, 4 μg/mL of IGF, 0.2% v/v B27, followed by selection by flow cytometry based on Oct4, Nanog, SOX2 and ABCG2 expression. In this subpopulation, ABCB5 expression (mRNA and protein using antibody SAB1300315 from Sigma) was increased