One fun image from long ago, never a cover illustration, but could have been one at some point, particularly for a fall issue of a throw-away-journal.  This is actually from a micrograph taken from a KO mouse CLICK5. The particulars of that particular KO mouse have long passed from my memory, but constructing the image is still fresh.  ha ha..

White part is the parietal cell nucleus, nose is red nucleolus) cytoplasm is pumpkin orange, and the green stem is a portion of of another cell.