Mechanistically, hypovitaminosis D was associated with higher levels of cytokines pivotal for natural killer (NK) cells (particularly interleukin-1β (IL-1β), IL-12, Interferon-γ (IFN-γ), and IL-8) and higher percentage of CD69+ NK cells in blood, which in turn correlated with chest pain presentation. This evidence concerns the gene CXCL8 and rickets.