Monocytes were isolated from randomly selected healthy male volunteers according to each Lp-PLA2 genotype ( wild-type Lp-PLA2 [ Lp-PLA2 ( V/V ) ] , the heterozygous V279F mutation [ LpPLA2 ( V/F ) ] and the homozygous V279F mutation [ Lp-PLA2 ( F/F ) ] ) and differentiated into macrophages .