Table 1.

Tumorigenic and metastatic properties of NIH 3T3 cells expressing Ras effector domain mutants

Transfected gene	Tumorigenicity*	Metastasis†
Vector alone (pDCR)	1/6  (8)‡	0/7
V12 ras (wt)	6/6  (2)	9/9 (3–4)
V12S35 ras	6/6  (3)	7/7 (6–7)
V12G37 ras	7/8  (4)‡	0/11
V12C40 ras	8/8  (3)	0/11
MEK	4/4  (3)	4/4 (5–6)
mos	4/4  (2)	4/4 (6–8)
R-Ras	3/3  (2–3)	0/3

^*Number of mice with tumors/total number of mice injected s.c. after 9 weeks. Elapsed times (in weeks) after injection before visible tumors appeared are shown in parentheses. 

^†Number of mice with lung metastases/total number of mice injected i.v. after 14 weeks. Elapsed times (in weeks) after injection before mice displayed signs of metastatic lung disease (labored breathing, loss of weight) are shown in parentheses. The presence or absence of lung metastases was verified by pathology. 

^‡Remaining mice developed tumors after 10–14 weeks.