Our study provides the first heritability estimates for innate and adaptive cytokine production and for lymphocyte proliferation after PMA-ionomycin and LPS stimulations in pig. Pro-inflammatory cytokines appear to show less heritable variation than adaptive system-related cytokines. Among the adaptive system-related cytokines, estimated heritability was weakest for cytokines produced after LPS stimulation, except for IL2 production. Heritability estimates for lymphocyte proliferation after CONA, PMA and LPS stimulations were moderate and that of lymphocyte proliferation after CONA stimulation was comparable to the value obtained by Edfors-Lilja and colleagues [15] . Moderate to high heritability estimates for cell count traits from hemogram or FACS also confirmed those previously obtained for WBC, total lymphocytes, neutrophils, eosinophils and some leukocyte subsets (for CD4 + and CD8 + T lymphocytes, cd T lymphocytes, CD11R1 + , CD11R1 + CD8a -, CD11R1 + CD8a + and CD16 + MHCII + ) [15, 16, 17, 19] . Likewise, our results confirmed the high heritability estimate for phagocytosis [15] . Conversly, a lower heritability estimate for CRP than previously reported was observed [15, 16] . Overall, the heritability estimates for these traits appear robust regardless of populations, environments and protocols.