2 and smk-1, RNAi inhibition of another PP4 regulatory subunit homologue, ppfr-2 (PP4R2 in humans), also reduced the median lifespan of worms infected at Day 6 of adulthood but had no effect on the ability of L4 larvae to resist infection (Fig 4A, 4B, 4G and 4H). This evidence concerns the gene PPP4C and infection.