FIGURE 1.

Unbalanced NIRs levels differentially affect cycling and non-proliferating cells. Left panel: overexpression of NIRs in proliferating cells causes mitotic abnormalities that can originate genetic instability, predisposing the cells to neoplastic growth. Indeed NIRs are found to be overexpressed in many tumour types, notably in breast, ovary, hepatocellular and gastric cancer (Çağatay and Chook, 2018; also see the TCGA database (https://www.cancer.gov/tcga, https://portal.gdc.cancer.gov/genes/ENSG00000108424). Right panel: in neurons, in which specific mutations in aggregation-prone proteins lead to the formation toxic aggregates that can undergo phase separation, NIRs can prevent or reverse the formation of such aggregates (see text for details) and mitigate their toxic effects, but fail to do so if expressed at insufficient ratios to the mutant proteins. Low levels of NIR can also impact on ciliary formation and function. The figure was created using BioRender.com.