General linear model analyses with particular haematological or flow-cytometry parameters as dependent factors, toxoplasmosis (binary) and sex (binary) as independent factors and age (continuous) as a confounding variable showed that toxoplasmosis correlates with several haematological and cytometric parameters, namely the leukocyte, CD19, CD16 + 56 and monocyte counts, mostly shifting the size of immune cell subpopulations in opposite directions in men and women (Tables 1 and 2). This evidence concerns the gene CD19 and toxoplasmosis.