*4.3.2. The β-globulins*

The β-globulins belong to group of globular proteins that migrate faster than γ-globulins in electrically charged solutions, but more slowly than α-globulins. The main components of the β-globulin fraction are transferrin and complement, which may correspond to the 2 subfractions (β<sup>1</sup> and β<sup>2</sup> ) identified in some animal species [81]. Other important proteins belonging to this fraction are: β<sup>2</sup> -microglobulin, C-reactive protein, ferritin, hemopexin, plasminogen, and angiostatin. Furthermore, in response to the stimulation by different antigens, some IgM immunoglobulins may migrate in the β region, while the IgA and IgE immunoglobulins in the β-γ interzone, which may also correspond to the β<sup>2</sup> subfraction, identified in some animal species [5].
