KISS1 and Delayed puberty: A recently published clinical study assessing serum levels of relaxin‐3 in patients with delayed puberty revealed that relaxin‐3 levels were significantly positively correlated with LH, FSH, and sex steroids.33 Because relaxin‐3 could stimulate the expression of Kiss‐1, GnRH, and pituitary gonadotropins by itself, it may be involved in coordinating feeding or energy balance with reproduction.