IGF2 and adrenal cortex neoplasm: This growth-promoting effect has also been demonstrated in other adrenocortical tumor cell lines: SW-13 cells do not express high levels of IGF2 and mouse Y1 cells do not express IGF1R; however, SW-13 cells proliferate rapidly in the presence of IGF2 [35] and Y1 cells proliferate rapidly when IGF1R is overexpressed [36].