SSR4 and infection: The results in A. phagocytophilum-infected ISE6 cells showed that pathogen infection significantly upregulated the expression of U2A8 (signal sequence receptor delta), 1I5B9 (ixodegrin-2A RGD containing protein), and 1I4G12 (unknown function) and downregulated the expression of 2I3A7 (NADH-ubiquinoe oxidoreductase) and 1I1H6 (glutathione S-transferase (GST)) in tick ISE6 cells (Figure 1).