A) Schematic presentation of all 3D7 var gene sequence analyses. Gene names, chromosomal location, transcriptional direction and domain structure are shown along with the cluster to which each gene was assigned by the sequences analyses. Sequences that could not be assigned to any cluster were named X. Three major var gene groups (group A-C), two intermediate groups group B/A and group B/C and two unique genes representing var1 and var2 var gene families were defined (framed). B) Sequence analyses of var genes from other P. falciparum strains than 3D7. Protein accession numbers, originating strain, domain structure and the closest related 3D7 var 5' sequence are shown along with sequence group allocations as defined in 3D7. *) The genes were assigned to group A, as their DBL1α sequences clustered together with other group A sequences in analysis of DBLα sequences. **) Pseudogene, belongs to the var1 family ^) Upstream sequences with atypically low similarity to upsB or upsC sequences.