As ghostship2 points out, you may need to subdivide the figure's mesh to improve the appearance of the vascularity.

On something completely different, male genitalia are usually an add-on to most figures.  When using the PBSDF node for a gens figure I found that there was an objectionable  seam between the genital figure and the hip of the parent figure.  The textures for male gens usually include a transparency map which blends the boundary so it matches the texture of the parent.  PBDSF doesn't have a transparency input, but it does have an alpha channel input, but connecting the trans map to the alpha channel didn't work.  RTFM!!  The Poser documentation states that you must use the Cycles image map, not the Poser image map!  This node can be found at Cycles>Texture>Image Texture.  When the transmap is opened in Image Texture node and connected to the alpha input, it works perfectly.