Table 1.

Results of the simulation study.

Model	intercept	Lasso	Li&Li	lik.boost	PathBoost
1	762.5 (14.4)	83.6 (2.6)	42.5 (1.1)	83.4 (2.4)	61.0 (1.7)
2	305.8 (5.1)	91.0 (2.7)	80.8 (1.9)	89.7 (2.7)	64.8 (1.8)
3	215.6 (4.1)	32.6 (0.9)	24.9 (0.8)	32.1 (0.9)	26.5 (0.7)
4	131.1 (2.4)	32.6 (0.9)	29.9 (0.7)	32.5 (0.9)	26.9 (0.7)
5	525.7 (9.9)	87.9 (2.6)	61.6 (1.5)	85.6 (2.2)	62.2 (1.6)
6	171.6 (3.3)	32.9 (0.9)	27.6 (0.7)	32.2 (0.9)	26.9 (0.8)

Predictive mean squared error, mean and standard errors (in parentheses), for an intercept-only model, the Lasso, the pathway-based procedure proposed in [9] (Li&Li), componentwise likelihood-based boosting (lik.boost), and boosting with pathway information (PathBoost) for six types of generating models.