SP3 and retinitis: In contrast, only two of the three UL40 peptides, VMAPRTLIL (SP1) and VMAPRTLVL (SP3), were observed in the majority of intraocular fluid specimens from CMV-retinitis patients (in which one of the peptides was observed in each patient), and VVAPRTLIL (SP2) was not present in their ocular fluid.