Phage pstS transcripts can be used to either produce additional copies of the periplasmic P-binding PstS protein, thus increasing the ability to acquire any available phosphate, or they can supplement the mRNA encoding the host pstS which is degraded together with the rest of the host transcriptome during the course of infection ([8]; Supplementary Fig. 1), thus providing a continuous supply of the PstS protein in the periplasm of the infected cell. The gene discussed is KLK4; the disease is infection.