Let's analyze the letter pairs based on their positions in the alphabet: 
J (10), L (12) — difference 2 
F (6), T (20) — difference 14 
H (8), O (15) — difference 7 
E (5), Z (26) — difference 21 
Check for common similarity: 
 Pairs FT, HO, and EZ both have letters with positional differences that are multiples of 7 (14, 7, 21 respectively). 
 Pair JL differs by 2, which does not follow this pattern. 
Hence, JL is the odd one out.