Table 2.

Viability ratio in the mutant mouse lines studied during the EUMODIC and SANGER-MGP programmes

tm1a subtype	Lethal	Subviable	Viable	Total	% Lethal lines
Promoter-driven	45	22	175	242	28
Promoterless	94	37	88	219	60
Total	139	59	263	461	43
% lines	30	13	57	100