**Figure 4.** **The establishment of the risk model CoCuLncSig and its basic performance demonstration.** (**A**) This visualization depicts the reduction of dimensionality for prognostic lncRNAs through the use of the LASSO algorithm. The left section of the visualization displays the LASSO coefficient profile for the examined prognostic lncRNAs, while the right section illustrates the LASSO regression process employing ten-fold cross-validation and minimal Lambda to identify eight prognostic lncRNAs. (**B**) The relationship between CoCu clusters, CoCu-DEG clusters, risks, and vital status in general is illustrated by the Sankey diagram. The diagram reveals that a notable portion of the C1 clusters in CoCu-DEG display high-risk scores, while the majority of its C2 clusters exhibit low-risk scores. (**C**) The box plots on the left panel demonstrate distinct statistical variations in the distributions of risk scores across the five CoCu clusters. On the right panel, the box plots exhibit statistically different distributions of risk scores in the two CoCu-DEG clusters. (**D**) Box plots display expression pattern of the 21 copper homeostasis/cuproptosis-regulated genes in the high- and low-risk groups. CoCuLncSig: copper homeostasis and cuproptosis regulated lncRNA signature; CoCu clusters: clusters identified by copper homeostasis and cuproptosis correlated genes; CoCu-DEGs: differentially expressed genes identified among CoCu clusters; CoCu-DEG clusters: clusters identified by CoCu-DEGs; DEGs: differentially expressed genes; LASSO: least absolute shrinkage and selection operator; A *P*-value less than 0.05 was considered significant for statistical analysis; The notation ^{*} represents *P*-value less than 0.05, ^{**} represents *P*-value less than 0.01, ^{***} represents *P*-value less than 0.001, and ^{****} represents *P*-value less than 0.0001.