When Ly2 parental and MK2 knockout tumors were orthotopically implanted into syngeneic mice (Balb/c), the MK2 KO cells demonstrated significantly lower tumor engraftment rates and tumor growth in 3 independent orthotopic xenograft studies with parental-wild type MK2 tumors (17 % vs 75 %, p = 0.0017) (Fig. 3A and B). The gene discussed is MAPKAPK2; the disease is neoplasm.