In order to avoid immune recognition in favor of a chronic infection, the 
malaria parasite Plasmodium falciparum has developed means to express clonally 
variant antigens at the surface of the infected erythrocyte (IE). Proteins of 
the var and rif multicopy gene families, encoding PfEMP1 and RIFINs, 
respectively, have been implicated in these processes. Here, we studied members 
of the latter family and present data revealing different subcellular 
localization patterns for RIFIN variants belonging to two distinct subgroups, 
which have been designated A- and B-type RIFINs. While A-type RIFINs were found 
to be associated with the parasite and transported to the surface of infected 
erythrocytes via Maurer's clefts, B-type RIFINs appeared to be mostly retained 
inside the parasite. However, expression of both subtypes does not seem to be 
mutually exclusive. Moreover, both A- and B-type variants were also expressed in 
the merozoite, present either in the apical region (A-type) or in the cytosol 
(B-type). The presence of RIFINs in merozoites suggests that antigenic variation 
in P. falciparum is not only restricted to parasite-derived proteins at the IE 
surface, but the phenomenon also prevails in other life cycle stages. 
Interestingly, some RIFIN variants were detected only in intracellular stages 
and not in merozoites, pointing to differential developmental expression 
patterns for distinct members of this large protein family.