Several FA proteins have been functionally linked to the process of mitotic DNA synthesis, also known as MiDAS. While the bulk of DNA synthesis occurs during S-phase, under conditions of replication stress, e.g., following treatment with aphidicolin (APH), DNA synthesis can still be observed during prophase/prometaphase. This mitotic DNA synthesis process is thought to be required for the resolution of late replication intermediates to allow sister chromatid disjunction in anaphase (Garribba et al., 2018) . MiDAS resembles a homologous recombination process known as break-induced DNA replication (HR/BIR), which promotes the repair and restart of collapsed DNA replication forks. Important roles for POLD3, RAD52, FANCD2 and SLX4 in MiDAS have been established (Bhowmick et al., 2016; Graber-Feesl et al., 2019) . We are particularly interested in the roles of the FANCD2 and FANCI proteins in MiDAS and are using several complementary approaches to address this question. These studies will yield important insight into a poorly understood process and shed light on the physiological function of the FA proteins.