Table 2.

K-ras mutations in lung neoplasms from ethylene oxide-exposed B6C3F1 mice.

		Codon 12 (GGT)			Codon 13 (GGC)			Codon 61 (CAA)
Treatment	K-ras mutations (%)	GAT	TGT	GTT	CGT	AGC	CGC	CGA	CAT	CAC
Controla	27/108 (25)	11b	5	1	0	0	3	2	4	1
Ethylene oxidec	23/23 (100)d	2	0	21	0	1	0	1	0	0
A/B adenoma	5/5 (100)	0	0	5	0	0	0	0	0	0
A/B carcinoma	18/18 (100)	2	0	16	0	1	0	1	0	0
50 ppm	8/8 (100)	0	0	8	0	0	0	0	0	0
100 ppm	15/15 (100)	2	0	13	0	1	0	1	0	0

^aConcurrent controls (8) combined with historical spontaneous lung neoplasms (100) from control B6C3F1 mice.

^bOne mutation was from a concurrent control.

^cMale and female B6C3F1 mice were exposed to 0, 50, or 100 ppm ethylene oxide by inhalation 6 hours/day, 5 days/week for 2 years.

^dTwo neoplasms had 2 mutations.