Immunogen: Synthetic peptide C-SQEKSRRVKEENPE from an internal region of human STK39 / SPAK (NP_037365.2). Percent identity by BLAST analysis: Human, Gorilla, Gibbon, Monkey, Marmoset, Rat, Hamster, Elephant, Panda, Dog, Bat, Horse, Rabbit, Opossum (100%); Mouse (93%); Platypus (86%).