PRPS1L1 is an autosomal phosphoribosyl pyrophosphate synthetase-related gene located on chromosome 7, functioning as a homolog of the X-linked PRPS1 gene 1. Like PRPS1, PRPS1L1 catalyzes synthesis of phosphoribosylpyrophosphate (PRPP), an essential substrate for nucleotide biosynthesis 1. The gene exhibits ribose phosphate diphosphokinase activity and participates in purine nucleotide biosynthetic pathways and ATP binding through protein homodimerization [GO annotations]. Regarding disease relevance, PRPS1L1 was identified as a candidate gene in the DFNB90 locus associated with autosomal recessive nonsyndromic hearing impairment, though no causal variants were identified upon sequencing 2. Additionally, PRPS1L1 deletion has been documented in complex chr7 rearrangements involving chromosome 7.1, where it may contribute to intellectual disability phenotypes 3. Clinically, PRPS1L1 emerged as a predictive protein in high-grade serous ovarian cancer prognosis, functioning as part of a three-protein panel (EIF2B1, PRPS1L1, MAPK13) with strong predictive performance for overall and progression-free survival 4.