Colony-forming ability and tumorigenicity of primary mesothelioma cells. Colony formation in vitro in 0.3% soft agar (A left panel). Colonies could be seen for NCI-Meso16, NCI-Meso17 and NCI-Meso21 cell cultures, each of which showed BAP1 mutations. Tumorigenic potential of these cell cultures was also investigated by subcutaneous injection of cells with matrigel in nude or SCID mice. Representative photographs of subcutaneous tumors derived following injection of NCI-Meso16, NCI-Meso17 and NCI-Meso21 cells is shown (A middle panel) along with the corresponding tumor growth curves (A right panel). Immunohistochemical staining for different markers showed the same pattern in tumor xenografts as in the matching primary cell cultures (B).