L-Azetidine-2-carboxylic acid is a proline analog. L-Azetidine-2-carboxylic acid upregulates the lipid autophagy marker LC3-II via activation of the PERK pathway. L-Azetidine-2-carboxylic acid increases pro-apoptotic BAX protein. L-Azetidine-2-carboxylic acid induces ATF6 cleavage and upregulates phosphorylated eIF2alpha levels. L-Azetidine-2-carboxylic acid induces ER stress, inducing protein misfolding and aggregation. L-Azetidine-2-carboxylic acid shows teratogenic, pro-inflammatory and pro-apoptotic effects[1][2][3][4][5][6][7][8][9].