Later, the failure of embryo implantation in steroidogenic factor-1 (SF-1) expression-dependent Bmal1-deleted female mice (Bmal1SF1d/d) was shown to be rescued by P4 supplementation or normal ovarian transplantation, demonstrating that insufficient ovarian P4 production is one of the primary causes of infertility in Bmal1 knockout female mice [73]. Here, BMAL1 is linked to Infertility.