Further laboratory investigation of the hypercalcaemia revealed increased 24-hours urine calcium (465 mg), decreased serum phosphorus levels at 1.3 mg/dl, increased serum parathyroid hormone levels (771 pg/ml), normal levels of serum free T3 (FT3), free T4 (FT4), thyroid stimulating hormone (TSH), calcitonine, carcino embryonic antigen (CEA), carcinoma antigen (CA) 15-9, CA 125, alpha feto protein (AFP). Here, CEACAM5 is linked to Hypercalcemia.