Table 1. The common features and differences between Ig produced by cancer cells and Ig produced by B cells.

	Ig produced by cancer cells		Ig produced by B cells
Heavy chain classes		α, γ, µ, ε and δ
Light chain types	Only κ-chain was found		κ- or λ-chain
Genetic processing	V(D)J is rearranged
	Germline configuration of C region Lacking V regionSpecial rearrangement pattern		Normal V(D)J rearrangement and class switching under control
Transcription	Regulated by cis-acting elements and transacting factors
	J1-5 all transcribed		One of J1-5 is chosen to be transcribed
Protein expression	Expression level is low		Expressing level is high
Protein structures	Unknown		Free antibody tetramer, IgA dimer, IgM pentamer
Post translational modification	N-acetyl and N-glycoyl neuraminic acid↑ N-acetylglucosamine↓		N-glycans attached to Fc region modulates Ig's biological activity
Function	Favoring tumor growth		Specific antigen receptor; combine Fc receptor; activate complement system

Abbreviation: Ig, immunoglobulin.