Figure 2. Transmission electron micrographs illustrating (a) an osteoblast, (b) an osteocyte, (c) a bone-lining cell, (d) AEFC-forming cementoblasts, (e) a CIFC-forming cementoblast, and (f) a cementocyte. AEFC, acellular extrinsic fiber cementum; CIFC, cellular intrinsic fiber cementum; and EF, extrinsic fibers.