What is the definition of Instances Blood Cells?

"Instances of blood cells are like the unexpected guests at a funeral, popping in just when you least expect them and reminding you that even the most vital of us can surprise you with their presence. Now, here's a darkly comedic example: 'The lone instance of blood cells in my coffee machine sent me into a fit of existential dread, wondering if I'd just been handed a cosmic horror gift.'"