  Renormalization of quantum loop effects generated from large fluctuations is
a hugely debatable topic of research these days which rules out the Primordial
Black Hole (PBH) formation within the framework of single-field inflation. In
this article, we briefly discuss that the correct implementation of
regularization, renormalization, and resummation techniques in a setup
described by an ultra-slow-roll phase sandwiched between two slow-roll phases
in the presence of smooth or sharp transitions can lead to a stringent
constraint on the PBH mass (i.e. ${\cal O}(10^{2}{\rm gm}$)), which we
advertise as a new No-go theorem. Finally, we will give some of the possible
way-outs using which one can evade this proposed No-go theorem and produce
solar/sub-solar mass PBHs.
