APOC1 and infection: Micro-3 highly expressed chemokines CCL3, CCL4, and MHC class I molecules, and Micro-5 had high expression of apolipoproteins (APOE, APOC1, and APOC4) and MHC class II molecules suggested that both Micro-3 and Micro-5 might be the activated, or response to infection, potentially disease-related microglia.