1
Other authors have shown that proline is conditionally essential.
2
L-Arginine (L-Arg) is a conditionally essential amino acid and a natural constituent of dietary proteins.
3
At one time it was thought to be a vitamin, but it is now classified as a " conditionally essential nutrient".
4
Furthermore, we performed a double gene deletion study and obtained 17 combinations consisting of 21 different genes, which were conditionally essential.