Here, we demonstrate that a Ras family protein, R-Ras2 (also called TC21 because it was cloned from a human teratocarcinoma cDNA library) (Drivas et al., 1990), which is able to transform cells and is up-regulated in several human cancers (Lee et al., 2011; Gutierrez-Erlandsson et al., 2013; Erdogan et al., 2007; Murphy et al., 2002), is regulated by a novel PTM, lysine fatty acylation. Here, RRAS2 is linked to cancer.