MAP4 and hypertensive disorder: For MAP4, a gene with several variants affecting simulated SBP, Sippy et al. [31] found that evidence for association with hypertension was much stronger in the selected sample than in the total unselected set of subjects: the p value from a mixed-model gene-based SNP-set test of association decreased from 0.31 in the unselected sample to 0.0068 in the selected sample.