The haematological crosstalk ensures the balanced production, differentiation, and maturation of blood cells required for normal physiological function and immune defense. Cytokines such as interleukins, colony-stimulating factors, erythropoietin, and thrombopoietin act as signaling molecules that stimulate progenitor cells to proliferate and differentiate into specific blood cell lineages. Progenitor cells also respond to inflammatory cytokines released during infection or tissue injury or pancytopenia increasing blood cell production to meet immune and homeostatic demands.  Disruption of this cytokine–progenitor interaction may lead to haematological disorders such as anaemia, leukopenia, or uncontrolled proliferation seen in leukaemia but also provides novel therapeutic targets for diseases.