Consider the descriptions below for three different lncRNAs, and determine whether they function in cis (C) or in trans (T). Your answer would be a three-letter string composed of letters C and T only, e.g. CCT.
( ) The tsiX RNA is transcribed from the X-inactivation center in the X chromosome that will not be inactivated. It is antisense with respect to Xist, repressing its transcription and function.
( ) The ANRIL lncRNA is an antisense transcript in a gene cluster expressing inhibitors of cell-cycle proteins. It silences the entire cluster by recruiting heterochromatin proteins of the Polycomb group.
( ) The PTENP1 lncRNA is similar to an mRNA that encodes the protein PTEN, and contains many of the miRNA response elements present in PTEN mRNA; it therefore protects the PTEN mRNA from miRNA-mediated silencing by acting as a decoy.