PRKX (protein kinase cAMP-dependent X-linked catalytic subunit) is a serine/threonine protein kinase that functions as a phylogenetically distinct member of the cAMP-dependent protein kinase family 1. The protein exhibits unique developmental and cellular functions beyond classical PKA signaling. PRKX plays a critical role in renal development through regulation of epithelial cell migration and morphogenesis, with expression restricted to ureteric bud epithelium during fetal kidney development 1. The kinase activates renal epithelial cell migration in the presence of cAMP and promotes branching morphogenesis independently of cAMP or hepatocyte growth factor 1. PRKX expression is developmentally regulated and shows tissue-specific patterns, with high expression in central nervous system and heart during early development, and variable levels across adult tissues including brain, kidney, and liver 2. In disease contexts, PRKX demonstrates oncogenic properties, being upregulated in nodular basal cell carcinoma 3 and contributing to osteosarcoma progression through interactions with CDC37 4. Additionally, PRKX expression confers resistance to sunitinib therapy in kidney carcinoma and melanoma cell lines 5. The gene's location on the X chromosome X it susceptible to abnormal recombination events with its Y-linked homolog PRKY, contributing to sex reversal disorders 6.