TWIST1 over-expression increased invasiveness of T98G cells in vivo. Equal numbers of GFP-labeled T98G Ctrl and T98G TW cells were injected into SCID mouse brains. At three months, whole brains were isolated and imaged using laser scanning confocal microscopy. For each tumor three optical sections for corresponding levels within each tumor are shown (left -top of the tumor; center - middle of the tumor; right - bottom of the tumor). Dashed white vertical and horizontal lines correspond to anterior border of brain and midline, respectively. The solid red line corresponds to the fixed coronal plane through the site of injection. Whole brain picture (lower left panel) demonstrates site of injection and approximate borders of the confocal images. In contrast to the fixed position of tumor growth at the injection site for the T98G Ctrl tumor, the T98G TW tumor demonstrates a marked degree of tumor cell migration anterior and posterior to the plane of injection and across the midline.