It is clear from the text that Gey's fundamental motivation for using HeLa cells is not to promote his own fame and fortune but because of his genuine interest in tissue culturing, and in addition his hope that through studying and experimenting on HeLa cells, a cure for cancer could be found. Note, for example, what he does in order to promote research on cancer cells:
Gey began sending Henrietta's cells to any scientist who might use them for cancer research... He sent shipments of HeLa cells to researchers in Texas, India, New York, Amsterdam, and many places between. These researchers gave them to more researchers, who gave them to more still.
if Gey had been in it for the fame and fortune, he would not have given away so many of Henrietta's cells for absolutely nothing, and he would have sold them or done something to ensure that he gained financially through the discovery of HeLa and its remarkable property of longevity. The fact that he gave the cells away to anybody who asked for them in order to research cancer cells strongly indicates his motive was purely altruistic. He did not seek to gain any personal advantage through his ownership of HeLa cells.