A
 
                  

                    
B
                  

                    
C
                  

                    
D
                  

                    
E
                  

                    
F
                  

                    
G
                  

                    
H
                  

                    
I
                  

                    
J
                  

                    
K
                  

                    
L
                  

                    
M
                  

                    
N
                  

                    
O
                  

                    
P
                  

                    
Q
                  

                    
R
                  

                    
S
                  

                    
T
                  

                    
U
                  

                    
V
                  

                    
W
                  

                    
X
                  

                    
Y
                  

                    
Z
                
              
              
Xenograft : tissues
              transfered from one species to another species, ie., monkey to
              human