This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cell Membrane and transpo protiens, Subject name: Physiology
Which is not an intermediate filament? 
Select and explain. 
A. Desmin, B. Vimentin, C. Tubulin, D. Keratin
C: Tubulin
Answer: C: Tubulin 
Explanation: Intermediate filaments - resist external pressure cell type specific: used as cellular markers Types Nuclear(Lamin-A,B,C) Vimentin like (Vimentin, desmin, GFAP, peripherin) Epithelial(Types 1,2 keratin) Axonal( Neurofilament proteins- NF-L,M,H)