Endoplasmic reticulum (ER) chaperone that functions to stabilize non-native glycoproteins and retain them in the ER until they are properly folded or targeted for ER associated degradation (ERAD) (Probable). Is essential for avoiding plant defense responses in cells with defective N-glycoproteins processing (PubMed:24280385). With co-chaperone DNJ1, coordinately functions during the tunicamycin-induced unfolded protein response (UPR) (PubMed:26487566). During biotrophic development, the UPR-associated function of DNJ1 appears to be more important than that of CNE1 (PubMed:26487566). Expression is increased in the absence of DNJ1. Leads only to slight reduction of virulence (PubMed:24280385, PubMed:26487566). Severely affects growth and displays an altered morphology, when the calnexin DNJ1 is also deleted (PubMed:26487566). Belongs to the calreticulin family.