MFS-type transporter; part of the gene cluster that mediates the biosynthesis of calbistrin A and related compounds. Calbistrin A is a secondary metabolite with an interesting structure that was recently found to have bioactivity against leukemia cells. It consists of two polyketides linked by an ester bond: a bicyclic decalin containing polyketide and a linear 12 carbon dioic acid structure (PubMed:30598828). Required for the secretion of calbistrin A and calbistrin C, as well as of related compounds decumbenone A, B and C (PubMed:30598828). Expression is induced in complex medium (Czapek yeast autolysate medium) supporting calbistrin production (PubMed:30598828). Expression is positively regulated by the calbistrin biosynthesis cluster-specific transcription factor calC (PubMed:30598828). Leads to an almost complete absence of calbistrin A and calbistrin C, and a decreased abundance of decumbenone A, B and C in the extracellular medium. Calbistrin A has been reported to possess a number of interesting bioactivities including antifungal active against Candida albicans and cytotoxic toward both healthy and leukemic human cells. Belongs to the major facilitator superfamily. TCR/Tet family.