PDGFA and cancer: Changes in mouse thymus and spleen were also investigated in a further study after return from the space shuttle STS-135 mission in which normal cell genes Il10, Il18bp, Il18r1, and Spp1 were found up-regulated, while Ccl7, Il6 were down-regulated, and cancer-related genes Casp8, Fgfr2, Figf, Hgf, IGF1, Itga4, Ncam1, Pdgfa, Pik3r1, Serpinb2, and Sykb were up-regulated as well, whereas Cdc25a, E2F1, Mmp9, and Myc showed decreased expression in thymus28.