TC21/R-Ras2His (Q72L) protein.Ras proteins are members of the superfamily of small GTPbinding proteins that function as molecular switches controlling a variety of signaling and transport pathways. TheRas family of GTP-binding proteins consists of the classicalRas (Ha,K,and N-), R-Ras, Rap1, Rap2, Ral, Rheb, Rin,Rit, TC21/R-Ras2, and M-Ras/R-Ras3 (M-Ras). TC21 isa Ras-like GTPase with high oncogenic potential that isfound mutated in some human tumors andfiverexpressedin breast cancer cell lines. It binds physically to c-Raf-1 ina GTP-dependent manner.TC21 (Q72L) is a constitutive active mutant of TC21. Purity 95% pure by SDS-PAGE