Finally, a comparative analysis of gene expression of cyp genes and ABC transporters in L4 was conducted as follows: (1) between the susceptible McMaster and the highly IVM- and MOX-resistant Berlin-selected isolate (BSI); (2) through a time course expression analysis for the BSI isolate during culture in the vehicle controls; and (3) differential gene expression analysis comparing the effects of IVM and MOX exposure on the resistant BSI isolate. The gene discussed is PPIG; the disease is bathing suit ichthyosis.