SPP1 and neoplasm: However, previous studies suggest that several of the identified proteins are potent stimulators of tumor cell proliferation or invasiveness, including SPARCL1 [12], IGF-BP2 [20], osteopontin [48], FAM3C [59], TREM2 [61], CD166 [28], prosaposin [1], and kininogen-1/bradykinin [42, 54].