eLife assessment
FKBP35 is the only FK506-binding protein present in the malaria-causing parasite Plasmodium falciparum, and has been considered a promising drug target due to its high affinity to the macrolide compound FK506, an immunosuppressant with antiplasmodial activity. This study demonstrates the essentiality of FKBP35 in parasite growth, based on compelling genetic evidence. The data also suggest that FK506 may exert its antimalarial activity through FKBP35-independent mechanisms that have not yet been characterised. This important study will be of interest to scientists working on the parasite biology and antimalarial drug development.