Five-dimensional and every higher dimension: three regular convex 
  
    
      
        n
      
    
    {\displaystyle n}
  -polytopes, all within the infinite family of regular 
  
    
      
        n
      
    
    {\displaystyle n}
  -simplexes, 
  
    
      
        n
      
    
    {\displaystyle n}
  -hypercubes, and 
  
    
      
        n
      
    
    {\displaystyle n}
  -orthoplexes.The fourth dimension is also the highest dimension where regular self-intersecting figures exist:

Two-dimensional: infinitaly many regular star polygons. Three-dimensional: four regular star polyhedra, the regular Kepler-Poinsot star polyhedra. Four-dimensional: ten regular star polychora, the Schläfli–Hess star polychora. They contain cells of Kepler-Poinsot polyhedra alongside regular tetrahedra, icosahedra and dodecahedra.
Cutaneous T-cell lymphoma (CTCL) is a class of non-Hodgkin lymphoma, which is a type of cancer of the immune system. Unlike most non-Hodgkin lymphomas (which are generally B-cell-related), CTCL is caused by a mutation of T cells. The cancerous T cells in the body initially migrate to the skin, causing various lesions to appear. These lesions change shape as the disease progresses, typically beginning as what appears to be a rash which can be very itchy and eventually forming plaques and tumors before spreading to other parts of the body. Signs and symptoms
The presentation depends if it is mycosis fungoides or Sézary syndrome, the most common, though not the only types. Among the symptoms for the aforementioned types are:  enlarged lymph nodes, an enlarged liver and spleen, and non-specific dermatitis. Cause
The cause of CTCL is unknown. Diagnosis
A point-based algorithm for the diagnosis for early forms of cutaneous T-cell lymphoma was proposed by the International Society for Cutaneous Lymphomas in 2005. Classification
Cutaneous T-cell lymphoma may be divided into the several subtypes. : 727–740  Mycosis fungoides is the most common form of CTCL and is responsible for half of all cases. A WHO-EORTC classification has been developed. Treatment
There is no cure for CTCL, but there are a variety of treatment options available and some CTCL patients are able to live normal lives with this cancer, although symptoms can be debilitating and painful, even in earlier stages.