FGFR1 and neoplasm: Other studies indicate that API5 inhibits BIM protein degradation through the FGF2-FGFR1-PKCδ-Erk signaling pathway or upregulates FGF2 and activates downstream pathways involving FGFR1, PKCδ, and ERK, ultimately leading to ubiquitin-dependent degradation of BIM, thereby attenuating apoptosis in tumor cells (Noh et al., 2014).