where did the tropic of cancer get its name
Tropic of Cancer When this line of latitude was named some 2,000 years ago, the Sun was in the constellation Cancer (Latin for crab) at the June solstice, the time each year that the Sun reaches its zenith at this latitude. Due to the precession of the equinoxes, this is no longer the case; today the Sun is in Taurus at the June solstice. The word "tropic" itself comes from the Greek "trope (τροπή)", meaning turn (change of direction, or circumstances), inclination, referring to the fact that the Sun appears to "turn back" at the solstices.
p53 Tumor protein p53, also known as p53, cellular tumor antigen p53 (UniProt name), phosphoprotein p53, tumor suppressor p53, antigen NY-CO-13, or transformation-related protein 53 (TRP53), is any isoform of a protein encoded by homologous genes in various organisms, such as TP53 (humans) and Trp53 (mice). This homolog (originally thought to be, and often spoken of as, a single protein) is crucial in multicellular organisms, where it prevents cancer formation, thus, functions as a tumor suppressor.[5] As such, p53 has been described as "the guardian of the genome" because of its role in conserving stability by preventing genome mutation.[6] Hence TP53 is classified as a tumor suppressor gene.[7][8][9][10][11] (Italics are used to denote the TP53 gene name and distinguish it from the protein it encodes.)