melanotic macules on skin macule. Benign. Dark spot labia (or lip). Analogous to lentigo simplex. Hyperpigmented basal keratinocytes & dermal melanophages. Slight ⬆️ in single basal melanocytes; NO nests. More info like this in Labial melanotic macules in atopic

They have the simplest genomes of any self-replicating, free-living organisms but can retain defined shapes by virtue of internal cytoskeletons

Arthur|Rowse, Gerry|Isaacson, Stuart|Lisk, Jerome P

You can look at the syringe illustrations below to help visualize this

10.1016/s0022-2275(20)33414-3 101

Micron-sized protein-free domains were also observed on ER membranes of central nervous system cells from hypothermic ground squirrels during hibernation ( Regulation of Membrane Physical State in Endoplasmic Reticulum The physical state of the ER (e.g., fluidity, lipid packing, membrane thickness, curvature) must be carefully regulated to fulfill its versatile functions