About CALR / Calreticulin:
Calreticulin, also known as CALR, is an essential protein and molecular chaperone. It is found in the endoplasmic reticulum of cells, and it can bind with calcium. Calreticulin has a number of functions within the body, including the fact that it can help to maintain correct calcium levels (by binding with the calcium and making it inactive, only to be released as and when needed) and it enables other proteins to fold in the right way, meaning that specific drugs will have more effect.
Calreticulin also functions as a binding agent for oligosaccharides which contain terminal glucose residues. Calreticulin can therefore reduce the amount of glucose residue within the cells. This also occurs if proteins within the endoplasmic reticulum add glucose to the cells. As well as this, it has been noted that calreticulin is a cardiac embryonic gene, meaning that it is crucial when embryos are developing. This has, at least, been determined in mice. Calreticulin has many different functions, in fact. It is seen in cancer cells and has a role in boosting macrophages that will then destroy cancerous cells. Unfortunately, not all cancer cells will be destroyed in this way due to the presence of a molecule with a CD47 signal which essentially blocks the calreticulin from promoting the macrophages. This has been a useful tool in cancer treatment, and the idea that blocking CD47 with antibodies and allowing the calreticulin to work to its fullest could be implemented is something that is currently being worked on.