Semimajor axis r_22SK (in kpc) of the star forming (SF) dwarf galaxies studied before in the Local Volume (LV), Virgo, Fornax, Hydra, Antlia (denoted jointly by VFHA, based on our previous work), and the four Abell clusters observed with the TNG (this paper) as a function of the luminosity – sech absolute magnitude M_SK. The cross in the upper left shows typical uncertainties in the two parameters.