Furthermore, a retrospective study from Portugal in returned adult travellers with non-severe falciparum malaria, found that there were statistically significant elevations in liver enzymes, specifically alanine aminotransferase (ALT) and aspartate aminotransferase (AST), in those who were treated with a standard 3 days course of artemether-lumefantrine (AL) compared to a historical cohort of patients treated with a quinine-doxycycline regimen. This evidence concerns the gene GPT and Plasmodium falciparum malaria.