CCL4 and infection: In general, both isolates also induced the upregulation of CCLs, ICAM-1 and VCAM-1 RNA in placental tissues at the late stages of infection (20 dpi); however, placentomes from animals infected with Nc-Spain7 exhibited higher CCL2, CCL4 and ICAM-1 expression levels than those infected with Nc-Spain1H (P < 0.05–0.001), especially in CO samples (Figure  1B).