PPM1B and viral infectious disease: Other proteins involved in the immune response, including NT5E (5’-nucleotidase, ecto), PPM1B (protein phosphatase, Mg2+/Mn2+ dependent, 1B), PSMB10 (proteasome subunit beta 1) and TRIM56 (tripartite motif containing 56), are down-regulated, which suggests that the sheep immunity is suppressed during overgrazing, thus increasing the likelihood of bacterial or viral infection and reduced growth performance [41, 42].