I know that blood platelets and erythrocytes do not have a nucleus. Are there more cells in the human body without a nucleus, such as pancreas, cartilage, or lung cells?
As far as I know, red blood cells and blood platelets are the only human cells in our body without a nucleus.
Erythrocytes and thrombocytes are the only human cells without a nucleus, as far as I know. However, if you count the gut as being part of the human body (in essence it is a continuation of the skin and as such it can be considered to be on our outside), then we are loaded with cells lacking a nucleus, namely all the bacteria that live in our intestines such as E. coli. Bacteria, being prokaryotes, lack a nucleus. In fact, there are ten times more bacteria than human cells in our gut (Wenner, 2007).
Wenner, Sci Am 2007